Commercial 

Airplanes 737

Service Bulletin

ALERT

Number: 737-27A1278

Original Issue: May 24, 2007

Revision 1: January 07, 2010

ATA System: 2741

SUBJECT: FLIGHT CONTROLS - Horizontal Stabilizer Trim Control System - Ballscrew and Ball

Nut Inspection and Lubrication

Export of this technology is controlled under the United States Export Administration Regulations (EAR) (15

CFR 730-774). An export license may be required before it is used for development, production or use by foreign

persons from specific countries. The controller of this data has the individual responsibility to abide by all export

laws.

ECCN: 9E991

BOEING PROPRIETARY, CONFIDENTIAL, AND/OR TRADE SECRET

Copyright © 2007 The Boeing Company

Unpublished Work - All Rights Reserved

Boeing claims copyright in each page of this document only to the extent that the page contains copyrightable

subject matter. Boeing also claims copyright in this document as a compilation and/or collective work.

This document includes proprietary information owned by The Boeing Company and/or one or more third parties.

Treatment of the document and the information it contains is governed by contract with Boeing. For more

information, contact The Boeing Company, P.O. Box 3707, Seattle, Washington 98124.

Boeing, the Boeing signature, the Boeing symbol, 707, 717, 727, 737, 747, 757, 767, 777, 787, Dreamliner,

BBJ, DC-8, DC-9, DC-10, KC-10, KDC-10, MD-10, MD-11, MD-80, MD-88, MD-90, P-8A, Poseidon and the

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connection with this document unless provided in writing by Boeing.

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ALERT ALERT

BLANK PAGE
Table of Contents

Revision Transmittal Sheet ............................................ 5

Summary ...................................................... 9

1. PLANNING INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

A. Effectivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

1. Airplanes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

2. Spares Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

B. Concurrent Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

C. Reason . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

D. Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

E. Compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

F. Approval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

G. Manpower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

H. Weight and Balance Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

I. Electrical Load Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

J. References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

1. Existing Data: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

2. Data supplied with this Service Bulletin: . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

3. Installation Drawings Used in the Preparation of this Service Bulletin: . . . . . . . . . . . 40

K. Publications Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

L. Interchangeability and Intermixability of Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

2. MATERIAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

A. Material - Price and Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

B. Industry Support Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

C. Parts Necessary For Each Airplane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

1. Kits/Parts: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

2. Parts and Materials Supplied by the Operator: . . . . . . . . . . . . . . . . . . . . . . . . 43

3. Parts Modified and Reidentified: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

4. Parts Removed and Not Replaced: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

D. Parts Necessary to Change Spares . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

E. Special Tooling - Price and Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

F. Special Tooling Necessary to do this Service Bulletin . . . . . . . . . . . . . . . . . . . . . . . 44

3. ACCOMPLISHMENT INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

A. GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

B. WORK INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

FIGURE 1: HORIZONTAL STABILIZER TRIM ACTUATOR - DETAILED INSPECTION OF THE

BALLSCREW, BALL NUT, AND THE ATTACHMENT FITTINGS- (GROUP 1 CONFIGURATION

1, GROUP 2 CONFIGURATION 1, AND GROUP 3 AIRPLANES) [Group 1-2, Configuration 1;

Group 3] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

FIGURE 2: HORIZONTAL STABILIZER TRIM ACTUATOR - DETAILED INSPECTION OF THE

BALLSCREW, BALL NUT, AND THE ATTACHMENT FITTINGS - (GROUP 1, CONFIGURATION

2 AIRPLANES) [Group 1, Configuration 2] . . . . . . . . . . . . . . . . . . . . . . . . . . 63

FIGURE 3: HORIZONTAL STABILIZER TRIM ACTUATOR - DETAILED INSPECTION OF THE

BALLSCREW, BALL NUT, AND, AND THE ATTACHMENT FITTINGS - (GROUP 2,

CONFIGURATION 2 AIRPLANES) [Group 2, Configuration 2] . . . . . . . . . . . . . . . 67

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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
FIGURE 4: LUBRICATION OF THE HORIZONTAL STABILIZER TRIM ACTUATOR (GROUP 1

CONFIGURATION 1, GROUP 2 CONFIGURATION 1, AND GROUP 3 AIRPLANES) [Group

1-2, Configuration 1; Group 3] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

FIGURE 5: LUBRICATION OF THE HORIZONTAL STABILIZER TRIM ACTUATOR (GROUP 1,

CONFIGURATION 2 AIRPLANES) [Group 1, Configuration 2] . . . . . . . . . . . . . . . 73

FIGURE 6: LUBRICATION OF THE HORIZONTAL STABILIZER TRIM ACTUATOR (GROUP 2,

CONFIGURATION 2 AIRPLANES) [Group 2, Configuration 2] . . . . . . . . . . . . . . . 75

FIGURE 7: HORIZONTAL STABILIZER TRIM ACTUATOR BALLSCREW AND BALL NUT -

REPAIR/REPLACE - (GROUP 1 CONFIGURATION 1, GROUP 2 CONFIGURATION 1, AND

GROUP 3 AIRPLANES) [Group 1-2, Configuration 1; Group 3] . . . . . . . . . . . . . . . 77

FIGURE 8: HORIZONTAL STABILIZER TRIM ACTUATOR BALLSCREW AND BALL NUT -

REPAIR/REPLACE - (GROUP 1, CONFIGURATION 2 AIRPLANES) [Group 1, Configuration

2] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

FIGURE 9: HORIZONTAL STABILIZER TRIM ACTUATOR BALLSCREW AND BALL NUT -

REPAIR/REPLACE - (GROUP 2, CONFIGURATION 2 AIRPLANES) [Group 2, Configuration

2] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

Appendix A: INSPECTION REPORT FORM FOR SB 737-27A1278 . . . . . . . . . . . . . . . . . . . 83

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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
Commercial 

Airplanes 737

Service Bulletin

ALERT

Revision Transmittal Sheet Number: 737-27A1278

Original Issue: May 24, 2007

Revision 1: January 07, 2010

ATA System: 2741

SUBJECT: FLIGHT CONTROLS - Horizontal Stabilizer Trim Control System - Ballscrew and Ball

Nut Inspection and Lubrication

This revision includes all pages of the service bulletin.

COMPLIANCE INFORMATION RELATED TO THIS REVISION

No more work is necessary on airplanes changed as shown in the original issue of this service bulletin. However,

Operators have to continue to do the repeat Detailed Inspection, Lubrication, and Overhaul in accordance with

Paragraph 1.E., Compliance, Table 1 or Table 2 as applicable.

Federal Aviation Administration (FAA) Notice of Proposed Rule Making FAA NPRM 2007-NM-256-AD, is related

to this service bulletin.

NOTE: The Operators that performed the initial Detailed Inspection, Lubrification, and Overhaul do not have

to do another initial inspection, but have to continue to do the repeat Detailed Inspection, Lubrication,

and Overhaul of the Horizontal Stabilizer Trim Actuator in accordance with Paragraph 1.E., Compliance,

Table 1 or Table 2 as applicable.

The Operators that incorporated service bulletin UMBRA CUSCINETTI, S.p.A. SB 07322-27-01 or

service bulletin LINEAR MOTION, LLC SB 7901708 or service bulletin SKYTRONICS, Inc. SB 93004

as given in WORK PACKAGE 4, have to continue to do the repeat Detailed Inspection, Lubrication,

and Overhaul of the Horizontal Stabilizer Trim Actuator in accordance with Paragraph 1.E., Compliance,

Table 1 or Table 2 as applicable.

The Operators that did not incorporate UMBRA CUSCINETTI S.p.A. or LINEAR MOTION LLC or

SKYTRONIC INC service bulletin, have to incorporate service bulletin UMBRA CUSCINETTI, S.p.A.

SB 07322-27-01 or service bulletin LINEAR MOTION, LLC SB 7901708 or service bulletin SKYTRONICS,

Inc. SB 93004 as given in WORK PACKAGE 4, and have to continue to do the repeat Detailed

Inspection, Lubrication, and Overhaul of the Horizontal Stabilizer Trim Actuator in accordance with

Paragraph 1.E., Compliance, Table 1 or Table 2 as applicable.

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REASON FOR REVISION

This revision is sent to correct the work instructions for the HSTA name plate identification information in WORK

PACKAGE 4 and to clarify some of the inspections necessary in WORK PACKAGE 1 and WORK PACKAGE

2. A note is also added in the compliance table to advise operators to do the lubrication task during the detailed

inspection task. In addition, reference to the "Horizontal Stabilizer Gearbox End Play Test as given OHM 27-45-11"

is added. This is because the Horizontal Stabilizer Gearbox Backlash Inspection is only given in the AMM for

737-600/700/800/900 airplane. The (OHM) Horizontal Stabilizer Gearbox End Play Test is a similar test and is

applicable to all 737-100/200/300/400/500 airplane variants.

These sections are changed:

1. Paragraph 1.D., Description: Affected Maintenance Zones are added for each airplane group.

2. Paragraph 1.E., Compliance: Notes (a) and (b) are added to Table 1 and Table 2 to recommend operators

to do a lubrication task during the detailed inspection task.

3. Paragraph 1.E., Compliance: Notice of Propose Rule Making 2007-NM-256-AD is added.

4. Paragraph 1.K., Publications Affected: Added Damage Tolerance Based Structural Inspection statement.

5. Paragraph 3.A, General Information: General Visual Inspection note added.

6. Paragraph 3.B, Work Instructions:

a. WORK PACKAGE 1:

– Added some notes, added more data to some step instructions, deleted some unnecessary step

instructions and correctly re-sequenced the steps.

b. WORK PACKAGE 2:

– Added some notes, added more data to some step instructions, deleted some unnecessary step

instructions and correctly re-sequenced the steps.

c. WORK PACKAGE 4:

– Step 1.a. revised to reference SB 737-27A1278 WORK PACKAGE 4 instead of 737-27A1278

WORK PACKAGE 3.

– Step 2.a. revised to reference SB 737-27A1278 WORK PACKAGE 4 instead of 737-27A1278

WORK PACKAGE 3.

– Step 3.b. revised to reference SB 737-27A1278 WORK PACKAGE 4 instead of 737-27A1278

WORK PACKAGE 3.

7. FIGURE 1: Step 10, inspection for large amount of grease that exits the Ball Nut and note (a) are removed.

8. FIGURE 2: Step 10, inspection for large amount of grease that exits the Ball Nut and note (a) are removed.

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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
9. FIGURE 7 sheet 2: Step 4, reference to Aircraft Maintenance Manual (AMM) removed and replaced with

internal reference note (b). Also the step table note (b) is revised to reference Horizontal Stabilizer Gearbox

End Play Test as given in OHM 27-45-11 instead of the Horizontal Stabilizer Gearbox Backlash inspection

as given in AMM 27-41-81/606.

10. FIGURE 8 sheet 2: Step 4, reference to Aircraft Maintenance Manual (AMM) removed and replaced with

internal reference note (b). Also the step table note (b) is revised to reference Horizontal Stabilizer Gearbox

End Play Test as given in OHM 27-45-11 instead of the Horizontal Stabilizer Gearbox Backlash inspection

as given in AMM 27-41-81/606.

11. FIGURE 9 sheet 2: Step 4, reference to Aircraft Maintenance Manual (AMM) removed and replaced with

internal reference note (b). Also the step table note (b) is revised to reference Horizontal Stabilizer Gearbox

End Play Test as given in OHM 27-45-11 instead of the Horizontal Stabilizer Gearbox Backlash inspection

as given in AMM 27-41-81/606.

The data given in Information Notice 737-27A1278 IN 01 is included in this revision.

Vertical lines are put on the left edge of each page, except in Paragraph 1.A., Effectivity, to show the location

of important changes.

Pages with no vertical lines have no important changes.

REVISION HISTORY

Original Issue: May 24, 2007

Revision 1: January 07, 2010

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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT

BLANK PAGE
Commercial 

Airplanes 737

Service Bulletin

ALERT

Summary Number: 737-27A1278

Original Issue: May 24, 2007

Revision 1: January 07, 2010

ATA System: 2741

SUBJECT: FLIGHT CONTROLS - Horizontal Stabilizer Trim Control System - Ballscrew and Ball

Nut Inspection and Lubrication

THIS BULLETIN IS SENT TO THE OPERATORS OF RECORD OF THE AIRPLANES SHOWN IN PARAGRAPH

1.A., EFFECTIVITY. IF AN AIRPLANE HAS BEEN LEASED OR SOLD, SEND THIS SERVICE BULLETIN TO

THE NEW OPERATOR. IF APPLICABLE SPARES HAVE BEEN SOLD, SEND THIS SERVICE BULLETIN TO

THE NEW OWNER.

CONCURRENT REQUIREMENTS

None.

BACKGROUND

This service bulletin is being issued to maintain the frequency of the detailed inspection of the Horizontal Stabilizer

Trim Actuator (HSTA) Ballscrew and Ball Nut as specified in the Maintenance Planning Document. This service

bulletin also gives instructions to remove/replace and repair the Horizontal Stabilizer Trim Actuator if a damaged

Ballscrew or Ball Nut is found. This service bulletin also adds the recommended intervals for repeat lubrication

and overhaul. Also, this service bulletin gives recommended compliance time for incorporation of the suppliers

service bulletins (service bulletin UMBRA CUSCINETTI, S.p.A. SB 07322-27-01, service bulletin LINEAR

MOTION, LLC SB 7901708, and service bulletin SKYTRONICS, Inc. SB 93004). The UMBRA CUSCINETTI

supplier service bulletin provides instructions to remove and replace the Ball Nut Tube Retainers on the 737

Horizontal Stabilizer Trim Actuator Ballscrew assembly with new Tube Retainers. The LINEAR MOTION supplier

service bulletin provides instructions to remove and replace the Ball Deflectors and the Ball Return Guide Clamps

on 737 Horizontal Stabilizer Trim Actuator Ballscrew assembly with new Ball Deflectors and Ball Return Guide

Clamps. The SKYTRONICS supplier service bulletin provides instructions to remove and replace the Return

Tube Clamps on the 737 Horizontal Stabilizer Trim Actuator Ballscrew assembly with new Return Tube Clamps.

The new parts installed will have sufficient stiffness to retain the load carrying balls in all known failure mode

conditions. The changes given in this bulletin will reduce the probability of loss of the primary and secondary

load paths of the Stabilizer Trim Actuator. Loss of primary and secondary load paths of the Stabilizer Trim

Actuator could result in the loss of control of the airplane.

This Service Bulletin also specifies the time for incorporation of the Boeing Service Bulletin 737-27-1046 Revision

1 (as applicable), dated April 5, 1974, if the service bulletin is not already incorporated. Boeing Service Bulletin

737-27-1046 Revision 1 applies to airplanes 737-100/200 with oil lubricators and provides instructions for

removing the existing oil lubricators and installation of a grease fitting on the Horizontal Stabilizer Trim Actuator

Ball Nut.

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NOTE: The Horizontal Stabilizer Trim Actuator Ballscrew Assembly 102J033-1 or 102J033-1 (OS) with Oil

Lubricator can not be reworked to a Horizontal Stabilizer Trim Actuator Ballscrew Assembly with grease

lubrication fitting as given in Boeing Service Bulletin 737-27-1046 Revision 1. Remove these Stabilizer

Trim Actuator Ballscrew Assemblies with Oil Lubricator and install 102J033-3 or 102J033-502 Horizontal

Stabilizer Trim Actuator Ballscrew Assembly

This service bulletin is being issued to maintain the frequency of the detailed visual inspection of the Horizontal

Stabilizer Trim Actuator Ballscrew and Ball Nut as specified in the Maintenance Planning Document. This service

bulletin also gives instructions to remove/replace and repair the Horizontal Stabilizer Trim Actuator if a damaged

Ballscrew or Ball Nut is found. This service bulletin also adds the recommended intervals for repeat lubrication

and overhaul.

After a Horizontal Stabilizer jackscrew incident related to a MD-80 airplane, Boeing initiated a design review of

the Boeing heritage horizontal stabilizer ballscrew primary and secondary load paths. During this review, one

757 operator reported a Horizontal Stabilizer Ballscrew with extensive corrosion. An investigation was initiated.

This investigation identified that a maintenance procedure to check the stabilizer Ballscrew primary load path

was required. In addition, the design review found that the Ball Nut Tube Retainers on the 737 Horizontal

Stabilizer Trim Actuator should be stiffened, so that the balls are retained within the assembly when the balls

are jammed and not free to circulate.

NOTE: Boeing also recommends that the Maintenance Planning Document (MPD) intervals be observed for

the "Lubrication" and "Detailed Inspection" actions prior to compliance with this service bulletin. The

"Lubrication" and "Detailed Inspection" done as given in this service bulletin satisfy the "Lubrication"

and "Detailed Inspection" requirements given in Maintenance Planning Document" (MPD).

Boeing Service Related Problem (SRP) 737CL-SRP-27-0153 is related to this bulletin.

ACTION (PRR 35005-261RS)

Get access to the Horizontal Stabilizer Trim Actuator and do the procedures that follow below at the intervals

shown in the compliance section.

1. DETAILED INSPECTION:

– Do the Detailed Inspection as given in Accomplishment Instructions, Paragraph 3.B., Work Instructions,

WORK PACKAGE 1 or WORK PACKAGE 2 (as applicable).

LUBRICATE THE HORIZONTAL TRIM ACTUATOR:

– Do the lubrication as given in Accomplishment Instructions, Paragraph 3.B., Work Instructions, WORK

PACKAGE 1 or WORK PACKAGE 2 (as applicable).

REMOVE and REPAIR/REPLACE THE HORIZONTAL TRIM ACTUATOR: Remove/Replace the Horizontal

Stabilizer Trim Actuator if damage is found as given in Accomplishment Instructions, Paragraph 3.B., Work

Instructions, WORK PACKAGE 1 or WORK PACKAGE 2 (as applicable).

NOTE: As an option, Operators can replace a damaged Horizontal Stabilizer Trim Actuator with a

serviceable Stabilizer Trim Actuator that is not new or not overhauled. Before the next flight, do

the Detailed Inspection and Lubrication for the replacement Stabilizer Trim Actuator as given in

this service bulletin and do the End Play Test as given in OHM 27-45-11. After the installation

follow the requirements of this service bulletin.

2. For airplanes with Horizontal Stabilizer Trim Actuator Ballscrew Assemblies with Oil Lubricators:

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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
a. CHECK the Horizontal Stabilizer Trim Actuator Ballscrew Assy Part Number. If you find Horizontal

Stabilizer Trim Actuator Ballscrew Assemblies 102J033-1 (Boeing Part Number 10-61302-1) or

102J033-1 (OS) (Boeing Part Number 10-61302-1), remove and install Stabilizer Ballscrew Assy

102J033-3 (Boeing Part Number 10-61302-2) or 102J033-502 (Boeing Part Number 10-61302-7) as

given in Accomplishment Instructions, Paragraph 3.B., Work Instructions, WORK PACKAGE 3.

NOTE: The Horizontal Stabilizer Trim Actuator Ballscrew Assembly 102J033-1 or 102J033-1 (OS)

with Oil Lubricator can not be reworked to a Horizontal Stabilizer Trim Actuator Ballscrew

Assembly with grease lubrication fitting as given in Service Bulletin 737-27-1046 Revision 1.

The 102J033-3 (Boeing Part Number 10-61302-2) is an oil lubricated Horizontal Stabilizer

Trim Actuator Ballscrew Assembly and operators have to incorporate Boeing Service Bulletin

737-27-1046 Revision 1 and the SKYTRONICS, Inc. SB 93004. The 102J033-502 (Boeing

Part Number 10-61302-7) is a grease lubricated Horizontal Stabilizer Trim Actuator Ballscrew

Assembly with reinforced Return Tube Clamps, and Operators do not have to incorporate

Boeing Service Bulletin 737-27-1046 Revision 1 and service bulletin SKYTRONICS, Inc. SB

93004.

b. INCORPORATE BOEING SERVICE BULLETIN 737-27-1046 Revision 1 as applicable: Incorporate

SB 737-27-1046 Revision 1 as given in Accomplishment Instructions, Paragraph 3.B., Work Instructions,

WORK PACKAGE 3.

NOTE: Service Bulletin 737-27-1046 Revision 1 is applicable for some 737-100/200 airplanes with

Ballscrew Oil Lubricators. This Service Bulletin provides instructions for the removal of the

existing Oil Lubricators and the installation of a grease fitting on the Horizontal Stabilizer Trim

Actuator Ball Nut. The Horizontal Stabilizer Trim Actuator Ballscrew Assembly 102J033-1 or

102J033-1 (OS) with Oil Lubricator can not be reworked to a Horizontal Stabilizer Trim Actuator

Ballscrew Assembly with grease lubrication fitting.

3. INCORPORATE ONE OF THE FOLLOWING SUPPLIER SERVICE BULLETINS as given in Accomplishment

Instructions, Paragraph 3.B., Work Instructions, WORK PACKAGE 4:

– UMBRA CUSCINETTI, S.p.A. SB 07322-27-01, Rev 00, Dated December 21, 2004: Install the new

Ball Nut Tube Retainers as given in this supplier service bulletin.

– LINEAR MOTION, LLC SB 7901708, Dated July 26, 2005: Install the new Ball Deflectors and Ball

Return Guide Clamps as given in this supplier service bulletin.

– SKYTRONICS, Inc. SB 93004, Dated September 01, 2005: Install the new Return Tube Clamps as

given in this supplier service bulletin.

4. REMOVE AND REPAIR/OVERHAUL THE HORIZONTAL STABILIZER TRIM ACTUATOR:

– Remove and repair/overhaul the Horizontal Stabilizer Trim Actuator as given in Accomplishment

Instructions, Paragraph 3.B., Work Instructions, WORK PACKAGE 5.

EFFECTIVITY

All 737-100/200/300/400/500 Airplanes divided in three groups. Refer to Paragraph 1.A.1., Airplanes for the list

of affected airplanes.

COMPLIANCE

Refer to Paragraph 1.E., Compliance.

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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
INDUSTRY SUPPORT INFORMATION

Boeing warranty remedies are available for airplanes in warranty as of June 14, 2001. Please refer to Paragraph

2.B., Industry Support Information.

MANPOWER

Refer to Paragraph 1.G., Manpower.

MATERIAL INFORMATION

None. Refer to Paragraph 2.A., Material - Price and Availability.

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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
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BLANK PAGE
Commercial 

Airplanes 737

Service Bulletin

ALERT

Number: 737-27A1278

Original Issue: May 24, 2007

Revision 1: January 07, 2010

ATA System: 2741

SUBJECT: FLIGHT CONTROLS - Horizontal Stabilizer Trim Control System - Ballscrew and Ball

Nut Inspection and Lubrication

THIS BULLETIN IS SENT TO THE OPERATORS OF RECORD OF THE AIRPLANES SHOWN IN PARAGRAPH

1.A., EFFECTIVITY. IF AN AIRPLANE HAS BEEN LEASED OR SOLD, SEND THIS SERVICE BULLETIN TO

THE NEW OPERATOR. IF APPLICABLE SPARES HAVE BEEN SOLD, SEND THIS SERVICE BULLETIN TO

THE NEW OWNER.

1. PLANNING INFORMATION

A. Effectivity

1. Airplanes

Refer to Service Bulletin Index Document D6-19567 Part 3 for Airplane Variable Number, Line

Number, and Serial Number data.

This service bulletin is for the airplanes shown below.

Refer to PRR 35005-261RS for data about this change.

GROUP CONFIGURATION DESCRIPTION

1 - 737-300/400/500 Airplanes

1 Airplanes with a separate Autopilot Actuator.

2 Airplanes with Primary Stabilizer Trim Actuator.

737-100/200 Airplanes delivered with Horizontal Stabilizer Trim

Actuator Oil Lubricator.

2 -

1 737-100/200 Airplanes that incorporated Service Bulletin 737-27-1046.

737-100/200 Airplanes that did not incorporate Service Bulletin

737-27-1046.

2

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GROUP CONFIGURATION DESCRIPTION

737-100/200 Airplanes delivered with grease fittings on the Stabilizer

Trim Actuator Ball Nut.

3 -

Airplane Models:

737-100, 737-200, 737-200C, 737-300, 737-400, 737-500

Variable Number Group

PA001 - PA022 2

PA099 2

PA231 - PA232 2

PC001 - PC005 2

PG001 - PG004 2

PG005 3

PG006 - PG075 2

PG199 2

PG201 - PG230 2

PG251 - PG255 2

PG271 - PG279 2

PG301 - PG314 2

PG331 - PG332 2

PG351 - PG356 2

PG375 2

PG401 - PG403 2

PG431 - PG442 2

PG471 - PG475 2

PG501 - PG505 2

PG571 - PG586 2

PG621 - PG630 2

PG651 - PG652 2

PG701 - PG705 2

PH001 2

PH011 - PH013 2

PH021 - PH024 3

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ALERT ALERT
Variable Number Group

PH701 - PH714 2

PH715 3

PH731 - PH732 2

PH741 - PH743 2

PJ001 - PJ003 2

PJ004 - PJ009 3

PJ031 - PJ032 2

PJ071 - PJ072 2

PJ101 - PJ109 2

PJ110 - PJ119 3

PJ201 - PJ216 2

PJ217 - PJ219 3

PJ301 - PJ302 1

PJ551 - PJ561 1

PJ601 - PJ615 1

PJ811 1

PJ816 - PJ817 1

PK026 - PK027 2

PK028 - PK029 3

PK041 - PK044 2

PK045 - PK053 3

PK061 - PK070 3

PK081 - PK082 3

PK091 - PK099 3

PK101 - PK103 3

PK111 - PK120 3

PK141 - PK146 3

PK201 - PK204 3

PK211 - PK223 3

PK231 - PK241 3

PK251 - PK258 3

PK271 - PK274 3

PK281 - PK289 3

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Variable Number Group

PK291 3

PK301 - PK318 3

PK341 3

PK351 - PK361 3

PK391 3

PK431 - PK433 3

PK451 - PK452 3

PK461 - PK469 3

PK495 3

PK501 - PK504 3

PK511 - PK515 3

PK519 3

PK521 - PK528 3

PK541 - PK565 3

PK581 3

PK591 - PK599 3

PK601 - PK617 3

PK621 - PK637 3

PK641 - PK642 3

PK661 - PK666 3

PK671 - PK681 3

PK691 - PK697 3

PK711 - PK716 3

PK731 - PK765 3

PK771 - PK779 3

PK801 - PK804 3

PK819 - PK827 3

PK830 3

PK861 - PK863 3

PK871 - PK874 3

PK881 - PK884 3

PK901 - PK938 3

PK971 - PK974 3

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ALERT ALERT
Variable Number Group

PL001 - PL028 3

PL061 3

PL081 3

PL101 - PL113 3

PL151 3

PL171 - PL172 3

PL201 - PL203 3

PL221 3

PL401 - PL417 3

PL421 3

PL441 3

PL451 - PL456 3

PL471 3

PL491 3

PL501 - PL506 3

PL551 - PL562 3

PL581 3

PL601 - PL603 3

PL611 3

PL621 - PL626 3

PL631 - PL632 3

PL711 - PL712 2

PL716 - PL717 2

PL718 - PL725 3

PL726 - PL729 2

PL730 - PL735 3

PL736 - PL742 2

PL743 - PL747 3

PL756 2

PL758 3

PL761 - PL763 2

PL764 - PL770 3

PL781 - PL782 2

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ALERT ALERT
Variable Number Group

PL783 - PL788 3

PL793 2

PL801 - PL803 2

PM001 - PM006 3

PM016 - PM017 3

PM021 - PM023 3

PM051 - PM065 3

PM066 1

PM101 - PM119 3

PM141 - PM142 3

PM171 3

PM181 3

PM251 - PM255 3

PM281 1

PM282 - PM283 3

PM381 - PM399 1

PM401 - PM417 1

PM541 - PM564 1

PN001 - PN002 3

PN021 - PN043 3

PN081 - PN086 3

PN101 - PN117 3

PN131 - PN163 3

PN401 - PN420 3

PN431 - PN433 3

PN451 - PN456 3

PN471 - PN474 3

PN481 3

PN491 - PN493 3

PN501 - PN502 3

PN511 - PN512 3

PN521 3

PP001 - PP054 1

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Variable Number Group

PP101 - PP169 1

PP181 - PP199 1

PP201 - PP205 1

PP221 1

PP231 - PP243 1

PP281 - PP286 1

PP301 - PP305 1

PP351 - PP353 1

PP376 - PP384 1

PP391 - PP393 1

PP401 - PP440 1

PP471 - PP475 1

PP501 - PP522 1

PP631 - PP634 1

PP651 - PP652 1

PP671 - PP699 1

PP701 - PP733 1

PP771 - PP779 1

PP801 - PP808 1

PP821 - PP827 1

PP831 - PP848 1

PP851 - PP852 1

PP861 - PP877 1

PP891 - PP899 1

PP901 - PP936 1

PP946 - PP948 1

PP951 - PP952 1

PP961 - PP967 1

PP981 - PP991 1

PP993 1

PQ001 - PQ016 1

PQ026 - PQ041 1

PQ051 - PQ092 1

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ALERT ALERT
Variable Number Group

PQ101 - PQ199 1

PQ201 - PQ202 1

PQ221 - PQ237 1

PQ241 - PQ243 1

PQ251 - PQ267 1

PQ281 - PQ299 1

PQ301 - PQ307 1

PQ331 - PQ332 1

PQ341 - PQ348 1

PQ361 - PQ373 1

PQ391 - PQ395 1

PQ401 - PQ418 1

PQ421 1

PQ431 - PQ438 1

PQ447 - PQ448 1

PQ451 1

PQ454 1

PQ471 - PQ475 1

PQ479 - PQ481 1

PQ486 - PQ487 1

PQ491 - PQ493 1

PQ771 - PQ772 1

PQ791 - PQ793 1

PQ801 - PQ805 1

PQ931 - PQ935 1

PQ951 1

PQ971 - PQ997 1

PR001 - PR017 1

PR021 - PR034 1

PR041 - PR045 1

PR061 - PR072 1

PR077 - PR082 1

PR091 - PR092 1

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ALERT ALERT
Variable Number Group

PR096 1

PR101 1

PR121 - PR122 1

PR131 - PR132 1

PR141 - PR143 1

PR161 - PR172 1

PR181 1

PS601 - PS631 1

PS636 - PS638 1

PS641 - PS644 1

PS651 - PS657 1

PS666 - PS669 1

PS691 - PS692 1

PS701 - PS706 1

PS751 - PS799 1

PS811 1

PS836 - PS837 1

PS841 - PS846 1

PS851 - PS852 1

PS856 1

PS861 - PS863 1

PS866 - PS868 1

PS871 - PS874 1

PS896 - PS897 1

PS901 - PS941 1

PS956 - PS957 1

PS961 - PS963 1

PS971 - PS978 1

PT001 - PT015 1

PT021 - PT031 1

PT041 - PT064 1

PT101 - PT105 1

PT121 - PT138 1

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ALERT ALERT
Variable Number Group

PT146 - PT148 1

PT161 - PT170 1

PT181 - PT188 1

PT211 - PT220 1

PT295 1

PT301 - PT309 1

PT331 - PT360 1

PT381 - PT399 1

PT401 - PT438 1

PT501 - PT517 1

PT561 - PT565 1

PT581 - PT586 1

PT611 - PT621 1

PT641 - PT644 1

PT651 - PT656 1

PT671 - PT672 1

PT681 - PT685 1

PT701 - PT703 1

PT716 - PT717 1

PT721 - PT725 1

PT801 - PT834 1

PT851 - PT854 1

PT871 - PT886 1

PT901 - PT930 1

PT971 - PT973 1

PT981 - PT985 1

PT996 1

PU001 - PU025 1

PU301 1

PU311 - PU313 1

PV001 - PV055 1

PV201 - PV209 1

PV226 - PV229 1

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ALERT ALERT
Variable Number Group

PV231 - PV237 1

PV271 - PV272 1

PV281 - PV287 1

PV296 1

PV301 - PV302 1

PV351 1

PV356 - PV357 1

PW001 - PW054 1

PW061 - PW068 1

PW072 1

PW086 - PW088 1

PW091 - PW094 1

PW101 - PW102 1

PW106 1

PW111 - PW120 1

PW156 - PW157 1

PW161 - PW171 1

PW201 - PW252 1

PW261 - PW268 1

PW271 - PW276 1

PW278 1

PW281 - PW293 1

PW296 1

PW301 - PW327 1

PW401 - PW408 1

PW411 - PW418 1

PW421 - PW424 1

PW431 - PW435 1

PW441 - PW450 1

PW461 - PW467 1

PW501 - PW504 1

PW511 - PW522 1

PW524 - PW550 1

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ALERT ALERT
Variable Number Group

PW556 - PW557 1

PW561 - PW564 1

PW571 - PW576 1

PW591 - PW596 1

PW611 - PW622 1

PW631 - PW637 1

PW661 - PW662 1

PW681 - PW683 1

PW701 - PW702 1

PW711 - PW717 1

PW741 - PW742 1

PW761 1

PW771 1

PW831 1

PW851 - PW856 1

PX071 2

PX701 2

PY001 - PY008 2

PY021 - PY022 2

PY031 2

PY036 - PY037 2

PY046 - PY047 2

PY048 3

PY051 - PY052 2

PY053 3

PY056 - PY057 3

PY101 2

PY102 - PY103 3

PY111 - PY113 2

PY131 2

PY132 - PY135 3

PY141 - PY143 3

PY151 - PY154 3

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ALERT ALERT
Variable Number Group

PY156 - PY157 3

PY161 - PY162 3

PY166 3

PY191 3

PY201 3

PY221 - PY222 3

PY231 3

PY241 - PY244 3

PY270 - PY275 3

PY281 3

PY286 3

PY301 - PY304 2

PY321 - PY323 2

PY341 - PY346 2

PY361 - PY362 2

PY381 2

PY401 3

PY409 - PY411 3

PY421 - PY422 3

PY441 3

PY451 3

PY461 - PY463 3

PY591 - PY595 3

PY611 - PY612 3

PY621 3

PY631 3

PY651 3

PY671 - PY672 3

PY721 3

PY741 3

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ALERT ALERT
2. Spares Affected

Examine your spares supply for Stabilizer Ballscrew Assembly part numbers given in the tables

below and incorporate the applicable supplier service bulletin to make sure that you do not install

Ballscrew Assemblies that are not reworked on airplanes that incorporated the applicable supplier

service bulletin:

Boeing Part NumberUmbra Cuscinetti,

S.p.A., Part Number

Name

Stabilizer Ballscrew 07322P000-01 (a) 10-62210-2

Assy

Stabilizer Ballscrew 07322P000-02 (a) 10-62210-3

Assy

(a) Incorporate Service Bulletin UMBRA CUSCINETTI, S.p.A.

SB 07322-27-01 on these Ballscrew assemblies prior to installing the Horizontal Stabilizer Trim Actuator with the spare

Ballscrew Assembly on the airplane, if the Horizontal Stabilizer Trim Actuator removed had a Ballscrew Assembly with

the UMBRA CUSCINETTI, S.p.A. SB 07322-27-01 incorporated.

Boeing Part NumberLinear Motion, LLC

Part Number

Name

Stabilizer Ballscrew 54032-003 (a) 10-61302-3

Assy

Stabilizer Ballscrew 54032-004 (a) 10-61302-4

Assy

Stabilizer Ballscrew 54032-005 (a) 10-61302-3

Assy

Stabilizer Ballscrew 54032-006 (a) 10-61302-3

Assy

Stabilizer Ballscrew 7826837 (a) 10-61302-5

Assy

(a) Incorporate Service Bulletin LINEAR MOTION, LLC SB

7901708 on these Ballscrew assemblies prior to installing

the Horizontal Stabilizer Trim Actuator with the spare

Ballscrew Assembly on the airplane, if the Horizontal Stabilizer Trim actuator removed had a Ballscrew Assembly with

the LINEAR MOTION, LLC SB 7901708 incorporated.

Boeing Part NumberSkytronics, Inc.

Part Number

Name

102J033-501 (.6250) 10-61302-2

(a)

Stabilizer Ballscrew

Assy

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ALERT ALERT
Boeing Part Number

Skytronics, Inc.

Part Number

Name

102J033-501 (.6243) 10-61302-2

(a)

Stabilizer Ballscrew

Assy

Stabilizer Ballscrew 102J033-5 (a) 10-61302-2

Assy

Stabilizer Ballscrew 102J033-3 (a) (b) 10-61302-2 (b)

Assy

Stabilizer Ballscrew 102J033-1 (c) 10-61302-1

Assy

Stabilizer Ballscrew 102J033-1 (OS) (c) 10-61302-1

Assy

(a) Incorporate Service Bulletin SKYTRONICS, Inc. SB 93004

on these Ballscrew assemblies prior to installing the Horizontal Stabilizer Trim Actuator with the spare Ballscrew Assembly

on the airplane, if the Horizontal Stabilizer Trim Actuator removed had a Ballscrew Assembly with the SKYTRONICS,

Inc. SB 93004 incorporated.

(b) The Ballscrew Actuator Assy P/N 102J033-3 became Boeing

P/N 10-61302-2 at the incorporation of Boeing Service Bulletin 737-27-1046 Revision 1 dated July, 1974.

(c) The Horizontal Stabilizer Trim Actuator Ballscrew Assembly

102J033-1 or 102J033-1 (OS) with Oil Lubricator can not be

reworked to a Horizontal Stabilizer Trim Actuator Ballscrew

Assembly with grease lubrication fitting as given in Boeing

Service Bulletin 737-27-1046 Revision 1.

B. Concurrent Requirements

None.

C. Reason

This service bulletin is being issued to maintain the frequency of the detailed inspection of the Horizontal

Stabilizer Trim Actuator Ballscrew and Ball Nut as specified in the Maintenance Planning Document.

This service bulletin also gives instructions to remove/replace and repair the Horizontal Stabilizer Trim

Actuator if a damaged Ballscrew or Ball Nut is found. This service bulletin also adds the recommended

intervals for repeat lubrication and overhaul. Also, this service bulletin gives recommended compliance

time for incorporation of the suppliers service bulletins (service bulletin UMBRA CUSCINETTI, S.p.A.

SB 07322-27-01, service bulletin LINEAR MOTION, LLC SB 7901708, and service bulletin

SKYTRONICS, Inc. SB 93004). The UMBRA CUSCINETTI supplier service bulletin provides instructions

to remove and replace the Ball Nut Tube Retainers on the 737 Horizontal Stabilizer Trim Actuator

Ballscrew assembly with new Tube Retainers. The LINEAR MOTION supplier service bulletin provides

instructions to remove and replace the Ball Deflectors and the Ball Return Guide Clamps on 737

Horizontal Stabilizer Trim Actuator Ballscrew assembly with new Ball Deflectors and Ball Return Guide

Clamps. The SKYTRONICS supplier service bulletin provides instructions to remove and replace the

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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
Return Tube Clamps on the 737 Horizontal Stabilizer Trim Actuator Ballscrew assembly with new

Return Tube Clamps. The new parts installed will have sufficient stiffness to retain the load carrying

balls in all known failure mode conditions. The changes given in this bulletin will reduce the probability

of loss of the primary and secondary load paths of the Stabilizer Trim Actuator. Loss of primary and

secondary load paths of the Stabilizer Trim Actuator could result in the loss of control of the airplane.

This Service Bulletin also specifies the time for incorporation of the Boeing Service Bulletin 737-27-1046

Revision 1 (as applicable), dated April 5, 1974, if the service bulletin is not already incorporated. Boeing

Service Bulletin 737-27-1046 Revision 1 applies to airplanes 737-100/200 with oil lubricators and

provides instructions for removing the existing oil lubricators and installation of a grease fitting on the

Stabilizer Trim Actuator Ball Nut.

NOTE: The Horizontal Stabilizer Trim Actuator Ballscrew Assembly 102J033-1 or 102J033-1 (OS)

with Oil Lubricator can not be reworked to a Horizontal Stabilizer Trim Actuator Ballscrew

Assembly with grease lubrication fitting as given in Boeing Service Bulletin 737-27-1046

Revision 1. Remove these Stabilizer Trim Actuator Ballscrew Assemblies with Oil Lubricator

and install 102J033-3 or 102J033-502 or Horizontal Stabilizer Trim Actuator Ballscrew

Assembly.

This service bulletin is being issued to maintain the frequency of the detailed visual inspection of the

Horizontal Stabilizer Trim Actuator Ballscrew and Ball Nut as specified in the Maintenance Planning

Document. This service bulletin also gives instructions to remove/replace and repair the Horizontal

Stabilizer Trim Actuator if a damaged Ballscrew or Ball Nut is found. This service bulletin also adds the

recommended intervals for repeat lubrication and overhaul.

NOTE: Boeing also recommends that the Maintenance Planning Document (MPD) intervals be

observed for the "Lubrication" and "Detailed Inspection" actions prior to compliance with this

service bulletin. The "Lubrication" and "Detailed Inspection" done as given in this service

bulletin satisfy the "Lubrication" and "Detailed Inspection" requirements given in Maintenance

Planning Document" (MPD).

Boeing Service Related Problem (SRP) 737CL-SRP-27-0153 is related to this bulletin.

Revision 1 is sent to correct the work instructions for the HSTA name plate identification information

in WORK PACKAGE 4 and to clarify some of the inspections necessary in WORK PACKAGE 1 and

WORK PACKAGE 2. A note is also added in the compliance table to advise operators to do the

lubrication task during the detailed inspection task. In addition, reference to the "Horizontal Stabilizer

Gearbox End Play Test as given OHM 27-45-11" is added. This is because the Horizontal Stabilizer

Gearbox Backlash Inspection is only given in the AMM for 737-600/700/800/900 airplane. The (OHM)

Horizontal Stabilizer Gearbox End Play Test is a similar test and is applicable to all

737-100/200/300/400/500 airplane variants.

1. Paragraph 1.D., Description: Affected Maintenance Zones are added for each airplane group.

2. Paragraph 1.E., Compliance: Notes (a) and (b) are added to Table 1 and Table 2 to recommend

operators to do a lubrication task during the detailed inspection task.

3. Paragraph 1.E., Compliance: Notice of Propose Rule Making 2007-NM-256-AD is added.

4. Paragraph 1.K., Publications Affected: Added Damage Tolerance Based Structural Inspection

statement.

5. Paragraph 3.A., General Information: General Visual Inspection note added.

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ALERT ALERT
6. Paragraph 3.B., Work Instructions:

a. WORK PACKAGE 1:

– Added some notes, added more data to some step instructions, deleted some unnecessary

step instruction and correctly re-sequenced the steps.

b. WORK PACKAGE 2:

– Added some notes, added more data to some step instructions, deleted some unnecessary

step instruction and correctly re-sequenced the steps.

c. WORK PACKAGE 4:

– Step 1.a. revised to reference SB 737-27A1278 WORK PACKAGE 4 instead of

737-27A1278 WORK PACKAGE 3.

– Step 2.a. revised to reference SB 737-27A1278 WORK PACKAGE 4 instead of

737-27A1278 WORK PACKAGE 3.

– Step 3.b. revised to reference SB 737-27A1278 WORK PACKAGE 4 instead of

737-27A1278 WORK PACKAGE 3.

7. FIGURE 1: Step 10, inspection for large amount of grease that exits the Ball Nut and note (a) are

removed.

8. FIGURE 2: Step 10, inspection for large amount of grease that exits the Ball Nut and note (a) are

removed.

9. FIGURE 7 sheet 2: Step 4, reference to Aircraft Maintenance Manual (AMM) removed and replaced

with internal reference note (b). Also the step table note (b) is revised to reference Horizontal

Stabilizer Gearbox End Play Test as given in OHM 27-45-11 instead of the Horizontal Stabilizer

Gearbox Backlash inspection as given in AMM 27-41-81/606.

10. FIGURE 8 sheet 2: Step 4, reference to Aircraft Maintenance Manual (AMM) removed and replaced

with internal reference note (b). Also the step table note (b) is revised to reference Horizontal

Stabilizer Gearbox End Play Test as given in OHM 27-45-11 instead of the Horizontal Stabilizer

Gearbox Backlash inspection as given in AMM 27-41-81/606.

11. FIGURE 9 sheet 2: Step 4, reference to Aircraft Maintenance Manual (AMM) removed and replaced

with internal reference note (b). Also the step table note (b) is revised to reference Horizontal

Stabilizer Gearbox End Play Test as given in OHM 27-45-11 instead of the Horizontal Stabilizer

Gearbox Backlash inspection as given in AMM 27-41-81/606.

D. Description

Get access to the Horizontal Stabilizer Trim Actuator and do the procedures that follow below at the

intervals shown in the compliance section.

1. DETAILED INSPECTION:

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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
– Do a detailed inspection for metal particles or corrosion products in the grease on the actuator

Ball Nut and Ballscrew. Clean the actuator Ballscrew. Visually inspect the actuator Ball Nut

and Ballscrew for damage, cracks, corrosion, and worn areas. Inspect for grease leakage.

Inspect for lifted or damaged Ball Nut Tube Retainers (UMBRA CUSCINETTI, S.p.A Ballscrew

Assemblies), or Ball Return Guide Clamps (LINEAR MOTION Ballscrew Assemblies), or

Return Tube Clamps (SKYTRONICS, Ballscrew Assemblies). Inspect the external areas of

the Stabilizer Trim Actuator, and the areas below the Stabilizer Trim Actuator, for loose ball

bearings. Move the Horizontal Stabilizer to a different setting to get access to the Ballscrew

area covered by the Ball Nut during the previous inspection. Repeat the inspections for the

new exposed area of the ballscrew. Replace the Horizontal Stabilizer Trim Actuator before

further flight if any of these conditions exist.

– Do the Detailed Inspection as given in Accomplishment Instructions, Paragraph 3.B., Work

Instructions, WORK PACKAGE 1 or WORK PACKAGE 2 (as applicable).

LUBRICATE THE HORIZONTAL STABILIZER TRIM ACTUATOR:

– Lubricate the Horizontal Stabilizer Trim Actuator Ballscrew, Ball Nut, and the upper and lower

Gimbals.

– Do the Lubrication as given in Accomplishment Instructions, Paragraph 3.B., Work Instructions,

WORK PACKAGE 1 or WORK PACKAGE 2 (as applicable).

REMOVE and REPAIR or REPLACE THE HORIZONTAL TRIM ACTUATOR: Remove/Replace

the Horizontal Stabilizer Trim Actuator if damage is found as given in Accomplishment Instructions,

Paragraph 3.B., Work Instructions, WORK PACKAGE 1 or WORK PACKAGE 2 (as applicable).

NOTE: As an option, Operators can replace a damaged Horizontal Stabilizer Trim Actuator with

a serviceable Stabilizer Trim Actuator that is not new or not overhauled. Before the next

flight, do the Detailed Inspection and Lubrication for the replacement Stabilizer Trim

Actuator as given in this service bulletin and do the End Play Test as given in OHM

27-45-11. After the installation follow the requirements of this service bulletin.

2. For airplanes with Horizontal Stabilizer Trim Actuator Ballscrew Assemblies with Oil Lubricators:

a. CHECK the Horizontal Stabilizer Trim Actuator Ballscrew Assy Part Number. If you find

Horizontal Stabilizer Trim Actuator Ballscrew Assemblies 102J033-1 (Boeing Part Number

10-61302-1) or 102J033-1 (OS) (Boeing Part Number 10-61302-1), remove and install Stabilizer

Ballscrew Assy 102J033-3 (Boeing Part Number 10-61302-2) or 102J033-502 (Boeing Part

Number 10-61302-7) as given in Accomplishment Instructions, Paragraph 3.B., Work

Instructions, WORK PACKAGE 3.

NOTE: The Horizontal Stabilizer Trim Actuator Ballscrew Assembly 102J033-1 or 102J033-1

(OS) with Oil Lubricator can not be reworked to a Horizontal Stabilizer Trim Actuator

Ballscrew Assembly with grease lubrication fitting as given in Service Bulletin. The

102J033-3 (Boeing Part Number 10-61302-2) is an oil lubricated Horizontal Stabilizer

Trim Actuator Ballscrew Assembly and operators have to incorporate Boeing Service

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: May 24, 2007

Revision 1: January 07, 2010 737-27A1278

32 of 83

BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
Bulletin 737-27-1046 Revision 1 and the Service Bulletin SKYTRONICS, Inc. SB

93004. The 102J033-502 (Boeing Part Number 10-61302-7) is a grease lubricated

Horizontal Stabilizer Trim Actuator Ballscrew Assembly with reinforced Return Tube

Clamps, and Operators do not have to incorporate Boeing Service bulletin

737-27-1046 Revision 1 and Service Bulletin SKYTRONICS, Inc. SB 93004.

b. INCORPORATE BOEING SB 737-27-1046 Revision 1 as applicable: Incorporate SB

737-27-1046 Revision 1 as given in Accomplishment Instructions, Paragraph 3.B., Work

Instructions, WORK PACKAGE 3.

NOTE: Service Bulletin 737-27-1046 Revision 1 is applicable for some 737-100/200 airplanes

with Ballscrew Oil Lubricators. This Service Bulletin provides instructions for the

removal of the existing Oil Lubricators and the installation of a grease fitting on the

Horizontal Stabilizer Trim Actuator Ball Nut. The Horizontal Stabilizer Trim Actuator

Ballscrew Assembly 102J033-1 or 102J033-1 (OS) with Oil Lubricator can not be

reworked to a Horizontal Stabilizer Trim Actuator Ballscrew Assembly with grease

lubrication fitting.

3. INCORPORATE ONE OF THE FOLLOWING SUPPLIER SERVICE BULLETINS as given in

Accomplishment Instructions, Paragraph 3.B., Work Instructions, WORK PACKAGE 4:

– Service Bulletin UMBRA CUSCINETTI, S.p.A. SB 07322-27-01, Rev 00, Dated December

21, 2004: Install the new Ball Nut Tube Retainers as given in this supplier service bulletin.

– Service Bulletin LINEAR MOTION, LLC SB 7901708, Dated July 26, 2005: Install the new

Ball Deflectors and Ball Return Guide Clamps as given in this supplier service bulletin.

– Service Bulletin SKYTRONICS, Inc. SB 93004, Dated September 01, 2005: Install the new

Return Tube Clamps as given in this supplier service bulletin.

4. REMOVE AND REPAIR/OVERHAUL THE HORIZONTAL STABILIZER TRIM ACTUATOR:

– Remove and repair/overhaul the Horizontal Stabilizer Trim Actuator as given in Paragraph

3.B., Work Instructions, WORK PACKAGE 5.

PLEASE SEND THE RESULTS FOR THE FAILED INSPECTIONS TO BOEING.

Send your report to: BOEING COMMERCIAL AIRPLANES GROUP ATTENTION: MANAGER, SERVICE

BULLETIN ENGINEERING P.O. BOX 3707, MAIL CODE 2H-36 SEATTLE, WA 98124-2207 USA

Revision 1:

No more work is necessary on airplanes changed as shown in the original issue of this service bulletin.

However, Operators have to continue to do the repeat Detailed Inspection, Lubrication, and Overhaul

as given in Paragraph 1.E., Compliance, Table 1 or Table 2 as applicable.

NOTE: The Operators that performed the initial Detailed Inspection, Lubrication, and Overhaul do

not have to do another initial inspection, but have to continue to do the repeat Detailed

Inspection, Lubrication, and Overhaul of the Horizontal Stabilizer Trim Actuator as given in

Paragraph 1.E., Compliance, Table 1 or Table 2 as applicable.

The Operators that incorporated service bulletin UMBRA CUSCINETTI, S.p.A. SB 07322-27-01

as given in WORK PACKAGE 4, have to continue to do the repeat Detailed Inspection,

Lubrication, and Overhaul of the Horizontal Stabilizer Trim Actuator as given in Paragraph

1.E., Compliance, Table 1 or Table 2 as applicable.

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

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Revision 1: January 07, 2010 737-27A1278

33 of 83

BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
The Operators that did not incorporate Service Bulletin UMBRA CUSCINETTI, S.p.A. SB

07322-27-01, have to incorporate Service Bulletin UMBRA CUSCINETTI, S.p.A. SB

07322-27-01 as given in WORK PACKAGE 4, and have to continue to do the repeat Detailed

Inspection, Lubrication, and Overhaul of the Horizontal Stabilizer Trim Actuator as given in

Paragraph 1.E., Compliance, Table 1 or Table 2 as applicable.

The work in this service bulletin is done in the maintenance zone(s) given below.

Group 1:

Affected Maintenance Zones

Model Zone

737-200 7-2

Group 1:

Affected Maintenance Zones

Model Zone

737-300, 737-400, 737-500 702

Group 2:

Affected Maintenance Zones

Model Zone

737-100, 737-200, 737-200C 7-2

Group 3:

Affected Maintenance Zones

Model Zone

737-200, 737-200C 7-2

E. Compliance

Boeing recommends that the operators do this service bulletin at the time given in Table 1 or Table 2,

as applicable.

NOTE: Boeing also recommends that the Maintenance Planning Document (MPD) intervals be

observed for the "Lubrication" and "Detailed Inspection" actions prior to compliance with this

service bulletin. The "Lubrication" and "Detailed Inspection" done as given in this service

bulletin satisfy the "Lubrication" and "Detailed Inspection" requirements given in Maintenance

Planning Document" (MPD).

Federal Aviation Administration (FAA) Notice of Proposed Rule Making FAA NPRM 2007-NM-256-AD,

is related to this service bulletin.

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34 of 83

BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
Group 1; Group 2, Configuration 1; Group 3:

Table 1 - Inspection, Lubrication, and Overhaul of the Horizontal Stabilizer Trim Actuator; Incorporation

of UMBRA CUSCINETTI, S.p.A. 07322-27-01 Service Bulletin, LINEAR MOTION, LLC 7901708 Service

Bulletin, and SKYTRONICS, Inc. 93004 Service Bulletin

Compliance Time Repeat Interval Notes

(Whichever Occurs First)

Condition Action

4,000 Flight Hours or (a)

2 years (Whichever

Occurs First).

Within 4,000 Flight Hours or

18 months from the last Detailed Inspection.

Detailed Inspection in

accordance with Paragraph 3.B., Work Instructions Steps 1.e.

and 1.o. WORK PACKAGE 1.

Group 1, Group 2

Configuration 1, and

Group 3 airplanes

2,000 Flight Hours or (b)

1 year (Whichever

Occurs First).

Within 2,000 Flight Hours or

1 Year from the last Lubrication.

Lubricate in accordance with Paragraph

3.B., Work Instructions

Step 1.p., WORK

PACKAGE 1.

24,000 Flight Hours

(Not to Exceed).

Before the accumulation of

24,000 Flight Hours since the

date of issuance of the original standard airworthiness

certificate or the date of issuance of the original export

certificate of airworthiness, or

within 24,000 Flight Hours

since last HSTA Overhaul.

Horizontal Stabilizer

Trim Actuator Overhaul

in accordance with Accomplishment Instructions, Paragraph 3.B.,

Work Instructions,

WORK PACKAGE 5.

Before the accumulation of -

24,000 Flight Hours since the

date of issuance of the original standard airworthiness

certificate or the date of issuance of the original export

certificate of airworthiness, or

within 24,000 Flight Hours

since last HSTA Overhaul.

Incorporate Service

Bulletin UMBRA CUSCINETTI, S.p.A. SB

07322-27-01, or Service Bulletin LINEAR

MOTION, LLC SB

7901708, or Service

Bulletin SKYTRONICS,

Inc. SB 93004, as applicable, in accordance

with Accomplishment

Instructions, Paragraph

3.B., Work Instructions,

WORK PACKAGE 4.

Repair/Replace the Before further flight -

Horizontal Stabilizer

Trim Actuator in accordance with Accomplishment Instructions,

Paragraph 3.B., Work

Instructions, WORK

PACKAGE 5.

Group 1, Group 2

Configuration 1, and

Group 3 airplanes

with damaged Horizontal Stabilizer

Trim Actuator

BOEING PROPRIETARY -

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Original Issue: May 24, 2007

Revision 1: January 07, 2010 737-27A1278

35 of 83

BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
Group 1; Group 2, Configuration 1; Group 3:

Table 1 - Inspection, Lubrication, and Overhaul of the Horizontal Stabilizer Trim Actuator; Incorporation

of UMBRA CUSCINETTI, S.p.A. 07322-27-01 Service Bulletin, LINEAR MOTION, LLC 7901708 Service

Bulletin, and SKYTRONICS, Inc. 93004 Service Bulletin

Compliance Time Repeat Interval Notes

(Whichever Occurs First)

Condition Action

(a) This task accomplishes a detailed inspection of the Horizontal Stabilizer Trim Actuator Ballscrew, Ball

Nut, Ball Nut Tube Retainers and Return Tubes, and also accomplishes a detailed inspection of the

lower and upper Gimbal and the attachment points. The detailed inspection done in accordance with

the service bulletin partially satisfies the intent of the task in accordance with 737-200 MPD Volume 1

Section 4 Item Number 4-27-06, or 737-300/400/500 MPD Volume 1 Section 6, Item Number B27-00-

00-F. You must accomplish the detailed inspection of the Horizontal Stabilizer Trim actuator as given

in this service bulletin to establish and stay compliant with this service bulletin.

(b) Accomplishment of this task satisfies the intent of the task in accordance with 737-200 MPD Volume

1 Section 3 Item Number 3-05-01, or 737-300/400/500 MPD Volume 1 Section 6, Item Number B12-

22-41-3A. However, you must accomplish this task as given in this service bulletin to establish and

stay compliant with this service bulletin.

Group 2, Configuration 2:

Table 2 - Inspection, Lubrication, and Overhaul of the Horizontal Stabilizer Trim Actuator; Incorporation

of 737-27-1046 Boeing Service Bulletin, and SKYTRONICS, Inc. 93004 Service Bulletin

Compliance Time Repeat Interval Notes

(Whichever Occurs First)

Condition Action

2,000 Flight Hours or 1 (d)

year (Whichever occurs

first).

Within 2,000 Flight Hours

or 1 year from the last inspection.

Detailed Inspection in accordance with Accomplishment

Instruction, Paragraph 3.B.,

Work Instructions, Steps 1.e.

and 1.o., WORK PACKAGE

2.

Group 2, Configuration 2 airplanes

500 Flight Hours or 2 (e)

months (whichever occurs first).

Within 500 Flight Hours or

2 months from the last Lubrication.

Lubricate in accordance with

Accomplishment Instruction,

Paragraph 3.B., Work Instructions, Step 1.p., WORK

PACKAGE 2.

20,000 Flight Hours (Not

To Exceed).

Before the accumulation of

20,000 Flight Hours since

the date of issuance of the

original standard airworthiness certificate or the date

of issuance of the original

export certificate of airworthiness, or within 20,000

Flight Hours since last HSTA overhaul.

Horizontal Stabilizer Trim

Actuator Overhaul in accordance with Accomplishment

Instructions, Paragraph 3.B.,

Work Instructions, WORK

PACKAGE 5.

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: May 24, 2007

Revision 1: January 07, 2010 737-27A1278

36 of 83

BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
Group 2, Configuration 2:

Table 2 - Inspection, Lubrication, and Overhaul of the Horizontal Stabilizer Trim Actuator; Incorporation

of 737-27-1046 Boeing Service Bulletin, and SKYTRONICS, Inc. 93004 Service Bulletin

Compliance Time Repeat Interval Notes

(Whichever Occurs First)

Condition Action

Repair/Replace the Horizon- Before further flight -

tal Stabilizer Trim Actuator

in accordance with Accomplishment Instructions,

Paragraph 3.B., Work Instructions, WORK PACKAGE 5.

Group 2 Configuration 2 airplanes with

damaged Horizontal Stabilizer

Trim Actuator

Before the accumulation of - (a)

20,000 Flight Hours since

the date of issuance of the

original standard airworthiness certificate or the date

of issuance of the original

export certificate of airworthiness, or within 20,000

Flight Hours since last HSTA overhaul.

Remove the Stabilizer

Ballscrew Assy 102J033-1

or 102J033-1 (OS) and install Stabilizer Ballscrew Assy 102J033-3 or 102J033-

502 in accordance with Accomplishment Instructions,

Paragraph 3.B., Work Instructions, WORK PACKAGE 3.

Group 2 Configuration 2 airplanes with Stabilizer Trim Actuator Ballscrew Assy 102J033-1 or

102J033-1 (OS)

installed on the

airplane.

(a) (b)

(c)

Before the accumulation of -

20,000 Flight Hours since

the date of issuance of the

original standard airworthiness certificate or the date

of issuance of the original

export certificate of airworthiness, or within 20,000

Flight Hours since last HSTA overhaul.

Incorporate Boeing Service

Bulletin 737-27-1046 Revision 1 in accordance with

Accomplishment Instructions, Paragraph 3.B., Work

Instructions, WORK PACKAGE 3.

Group 2, Configuration 2 airplanes with Horizontal Stabilizer

Trim Actuator

Ballscrew Assy

with Oil Lubricators

Before the accumulation of - (a)

20,000 Flight Hours since

the date of issuance of the

original standard airworthiness certificate or the date

of issuance of the original

export certificate of airworthiness, or within 20,000

Flight Hours since last HSTA overhaul.

Incorporate SKYTRONICS,

Inc. SB 93004 in accordance

with Accomplishment Instructions, Paragraph 3.B., Work

Instructions, WORK PACKAGE 4.

Group 2, Configuration 2 airplanes

(a) The Horizontal Stabilizer Trim Actuator Ballscrew Assembly 102J033-1 or 102J033-1 (OS) with Oil Lubricator can not be reworked to a Horizontal Stabilizer Trim Actuator Ballscrew Assembly with grease lubrication fitting in accordance with Boeing Service Bulletin 737-27-1046 Revision 1. If you find Stabilizer

Ballscrew Assemblies 102J033-1 or 102J033-1 (OS) installed on the airplane, remove and install 102J033-

3 or 102J033-502 Horizontal Stabilizer Trim Actuator Ballscrew Assembly.

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Original Issue: May 24, 2007

Revision 1: January 07, 2010 737-27A1278

37 of 83

BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
Group 2, Configuration 2:

Table 2 - Inspection, Lubrication, and Overhaul of the Horizontal Stabilizer Trim Actuator; Incorporation

of 737-27-1046 Boeing Service Bulletin, and SKYTRONICS, Inc. 93004 Service Bulletin

Compliance Time Repeat Interval Notes

(Whichever Occurs First)

Condition Action

(b) Airplanes with Horizontal Stabilizer Trim Actuator Ballscrew Assemblies with Oil Lubricators can be

changed to Trim Actuators Ballscrew Assemblies with grease lubricator by removing the existing Oil Lubricator Reservoirs and installing a Grease Fitting in accordance with Boeing Service Bulletin 737-27-

1046 Revision 1, dated April 05, 1974.

(c) After you incorporate Boeing Service Bulletin 737-27-1046 Revision 1 (after you install the grease lubricator as given in SB 737-27-1046) the airplane will belong to Group 1 Configuration 1 airplanes. Use the

Detailed Inspection, Lubrication, and Overhaul intervals given in Table 1.

(d) This task accomplishes a detailed inspection of the Horizontal Stabilizer Trim Actuator Ballscrew, Ball

Nut, Ball Nut Tube Retainers and Return Tubes, and also accomplishes a detailed inspection of the

lower and upper Gimbal and the attachment points. The detailed inspection done in accordance with the

service bulletin partially satisfies the intent of the task in accordance with 737-200 MPD Volume 1 Section

4, Item Number 4-27-06. You must accomplish the detailed inspection of the Horizontal Stabilizer Trim

Actuator as given in this service bulletin to establish and stay compliant with this service bulletin.

(e) Accomplishment of this task satisfies the intent of the task in accordance with 737-200 MPD Volume 1

Section 3, Item Number 3-05-01. However you must accomplish this task as given in this service bulletin

to establish and stay compliant with this service bulletin.

F. Approval

This service bulletin was examined by the Federal Aviation Administration (FAA). The changes specified

in this service bulletin comply with the applicable regulations and are FAA approved, as well as European

Aviation Safety Agency (EASA)/Joint Aviation Authorities (JAA) approved for all EASA/JAA approved

airplanes listed in the service bulletin effectivity. This service bulletin and its approval were based on

the airplane in its original Boeing delivery configuration or as modified by other approved Boeing

changes.

If an airplane has a non-Boeing modification or repair that affects a component or system also affected

by this service bulletin, the operator is responsible for obtaining appropriate regulatory agency approval

before incorporating this service bulletin.

G. Manpower

The table below shows an estimate of the task-hours necessary for each airplane to do a detailed

inspection, to lubricate, and to replace the horizontal stabilizer trim actuator. This estimate is for direct

labor only, done by an experienced crew. Adjust the estimate with operator task-hour data if necessary.

The estimate does not include lost time. These are some examples of lost time:

— Time to adjust to the workplace

— Time to schedule the work

— Time to examine the work

— Time to cure the materials

— Time to make the parts

— Time to find the tools.

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38 of 83

BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
Number of Per- Task-Hours Elapsed Hours

sons

Task

Open Access 1 1.25 1.25

Detailed Inspection 2 4.0 2.0

Lubrication 2 2.5 1.25

Replace Stabilizer Trim 2 8.0 4.0

Actuator (b)

Close Access 1 1.25 1.25

Test 2 2.0 1.0

TOTAL FOR EACH AIRPLANE (a) 11.0 6.75

(a) Total hours does not include actuator replacement.

(b) Hours are for replacement only, additional time required for Stabilizer Trim Actuator overhaul.

H. Weight and Balance Changes

None.

I. Electrical Load Data

Not changed.

J. References

1. Existing Data:

a. Engineering Change Memo PRR 35005-261RS

b. Boeing Service Bulletin 737-27-1046

c. Boeing Service Related Problem (SRP) 737CL-SRP-27-0153

d. Component Maintenance Manual (CMM) 27-41-81, 27-45-11, 27-45-12

e. Federal Aviation Administration (FAA) Notice of Proposed Rule Making 2007-NM-256-AD

f. Overhaul Manual (OHM) 27-45-11

g. Standard Overhaul Practices Manual (SOPM) 20-50-10

h. 737-100/200 Aircraft Maintenance Manual (AMM) 12-22-41, 27-41-121, 27-41-81

i. 737-200 Maintenance Planning Data (MPD) Volume 1Section 1, Volume 1Section 3, Volume

1Section 4

j. 737-300/400/500 Aircraft Maintenance Manual (AMM) 12-22-41, 27-41-81

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39 of 83

BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
k. 737-300/400/500 Maintenance Planning Data (MPD) Volume 1Section 4, Volume 1Section

6

l. LINEAR MOTION, LLC Service Bulletin 7901708

m. SKYTRONICS, Inc. Service Bulletin 93004

n. UMBRA CUSCINETTI, S.p.A. Service Bulletin 07322-27-01

o. LINEAR MOTION, LLC Component Maintenance Manual (CMM) 27-41-01

p. SKYTRONICS, Inc. Component Maintenance Manual (CMM) 27-40-03

q. UMBRA CUSCINETTI, S.p.A. Component Maintenance Manual (CMM) 27-41-01

a. Engineering Change Memo PRR 35005-261RS

b. Boeing Service Bulletin 737-27-1046

c. Boeing Service Related Problem (SRP) 737CL-SRP-27-0153

d. Component Maintenance Manual (CMM) 27-41-81, 27-45-11, 27-45-12

e. Federal Aviation Administration (FAA) Notice of Proposed Rule Making 2007-NM-256-AD

f. Overhaul Manual (OHM) 27-45-11

g. Standard Overhaul Practices Manual (SOPM) 20-50-10

h. 737-100/200 Aircraft Maintenance Manual (AMM) 12-22-41, 27-41-121, 27-41-81

i. 737-200 Maintenance Planning Data (MPD) Volume 1Section 1, Volume 1Section 3, Volume

1Section 4

j. 737-300/400/500 Aircraft Maintenance Manual (AMM) 12-22-41, 27-41-81

k. 737-300/400/500 Maintenance Planning Data (MPD) Volume 1Section 4, Volume 1Section

6

l. LINEAR MOTION, LLC Service Bulletin 7901708

m. SKYTRONICS, Inc. Service Bulletin 93004

n. UMBRA CUSCINETTI, S.p.A. Service Bulletin 07322-27-01

2. Data supplied with this Service Bulletin:

None.

3. Installation Drawings Used in the Preparation of this Service Bulletin:

None.

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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
K. Publications Affected

1. Publications:

Publication Chapter-Section

737-300/400/500 AMM 12-22-41,

737-300/400/500 AMM 27-41-81

737 Maintenance Manual

737 Component Maintenance Manual CMM 27-45-11

737-100/200 Maintenance Planning Docu- Section 1

ment (MPD)

737-300/400/500 Maintenance Planning Section 6

Document (MPD)

2. Damage Tolerance Based Structural Inspections:

Boeing has evaluated the repairs and/or changes in this service bulletin for effects on Fatigue

Critical Structure (FCS) and for changes to Damage Tolerance Inspections (DTI) required in the

Maintenance Program. This service bulletin does not affect FCS, therefore DTIs are not necessary.

L. Interchangeability and Intermixability of Parts

Refer to Illustration Parts Catalog (IPC) for the Interchangeable parts.

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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
BOEING PROPRIETARY -

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42 of 83

BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT

BLANK PAGE
2. MATERIAL INFORMATION

A. Material - Price and Availability

None.

B. Industry Support Information

Boeing warranty remedies are available for 737 airplanes in warranty as of June 14, 2001. For man-hour

reimbursement for airplanes in warranty as of that date, send a warranty claim to Boeing Commercial

Airplanes Group - Warranties. The parts for airplanes in warranty as of that date will be supplied at no

charge. Send a purchase order for the parts to Boeing Spares. Please refer to this service bulletin

number and reference the airplane variable number in your purchase order.

C. Parts Necessary For Each Airplane

1. Kits/Parts:

None.

2. Parts and Materials Supplied by the Operator:

Part Number / Specifi- QTY Name Notes

cation

7901976 - Kit, 737 HSTA Clamp (a)

102C238-1 - Tube Clamp Kit (b)

As Neces- Grease Recommended (c)

sary

BMS 3-33

As Neces- Grease Alternate to BMS 3-33

sary

MIL-G-23827

As Neces- General Purpose Oil

sary

MIL-L-7870

Protective Enamel (Clear), Hydraulic (c)

Fluid Resistant

As NecessaryBMS 10-60, Type 2,

Clear or equivalent

As Neces- Ink or Paste Ink (d)

sary

Permanent Marking

Material

(a) You need this kit if you incorporate service bulletin LINEAR MOTION, LLC SB 7901708. Order the

kit from Boeing Spares.

(b) You need this part if you incorporate service bulletin SKYTRONICS, Inc. SB 93004. Order the

number of parts required as given in the Skytronics, Inc. service bulletin from Boeing Spares.

(c) See the Qualified Products List at the end of the Boeing Material Specification (BMS) for supplier

data.

(d) Refer to SOPM 20-50-10 for the list of permanent marking materials.

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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
3. Parts Modified and Reidentified:

None.

4. Parts Removed and Not Replaced:

None.

D. Parts Necessary to Change Spares

None.

E. Special Tooling - Price and Availability

None.

F. Special Tooling Necessary to do this Service Bulletin

No special tools or equipment are necessary to do the change in this service bulletin. But, maintenance

and overhaul tools in the manuals given in Paragraph 1.J., References, can be necessary. Examine

operator tool supply to make sure all necessary tools are available.

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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
3. ACCOMPLISHMENT INSTRUCTIONS

A. GENERAL INFORMATION

CAUTION: KEEP THE WORK AREA, WIRES AND ELECTRICAL BUNDLES CLEAN OF METAL

PARTICLES OR CONTAMINATION WHEN YOU USE TOOLS. UNWANTED MATERIAL,

METAL PARTICLES OR CONTAMINATION CAUGHT IN WIRE BUNDLES CAN CAUSE

DAMAGE TO THE BUNDLES. DAMAGED WIRE BUNDLES CAN CAUSE SPARKS OR

OTHER ELECTRICAL DAMAGE.

NOTE: 1. Manual titles are referred to by acronyms. Refer to Paragraph 1.J., References, for

definition of the acronyms.

2. Obey all of the warnings and cautions given in the specified manual sections.

3. The work instructions are divided into work packages. Task Hours and Elapsed Hours

for each package are given in Paragraph 1.G., Manpower. You can do each work

package independently.

4. Use the approved fastener and process material substitutions in accordance with

737 SRM, Chapter 51. Alternate fasteners are listed in 737 SRM Chapter 51 and

Boeing Drawing 65-88700.

5. A Detailed Inspection is defined as: An intensive examination of a specific item,

installation, or assembly to detect damage, failure, or irregularity. Available lighting

is normally supplemented with a direct source of good lighting at an intensity deemed

appropriate. Inspection aids such as mirrors, magnifying lenses, etc. may be

necessary. Surface cleaning and elaborate procedures may be required.

6. A General Visual Inspection is defined as: A visual examination of an interior or

exterior area, installation or assembly to detect obvious damage, failure or irregularity.

This level of inspection is made from within touching distance unless otherwise

specified. A mirror may be necessary to ensure visual access to all surfaces in the

inspection area. This level of inspection is made under normal available lighting

conditions such as daylight, hangar lighting, flashlight or drop-light and may require

removal or opening of access panels or doors. Stands, ladders or platforms may be

required to gain proximity to the area being checked.

7. These work instructions refer to procedures included in other Boeing documents.

When the words "refer to" are used and the operator has an accepted alternative

procedure, the accepted alternative procedure can be used. When the words "in

accordance with" are included in the instruction, the procedure in the Boeing document

must be used.

8. Operators will find the term "Stabilizer Trim Actuator" in the Airplane Maintenance

Manual documents. The "Stabilizer Trim Actuator" includes the Ball Nut, Jackscrew,

and Jackscrew Gearbox. The term "Jackscrew" called out in the Airplane Maintenance

Manual documents is referred to as "Ballscrew" in this service bulletin.

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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
B. WORK INSTRUCTIONS

WORK PACKAGE 1 (GROUP 1, GROUP 2 CONFIGURATION 1, and GROUP 3 Airplanes): Detailed

Inspection and Lubrication of the Horizontal Stabilizer Trim Actuator Ballscrew, Ball Nut, and

attachment (Gimbal) fittings

1. Refer to Paragraph 1.E., Compliance, Table 1, for the interval at which the Detailed Inspection

and Lubrication of Stabilizer Trim Actuator Ballscrew, Ball Nut, and attachment fittings (Gimbal

Fittings) need to be accomplished/repeated.

a. Get access to the horizontal Stabilizer Trim Actuator assembly through service access door

3701. Refer to 737-200 MPD Volume 1 Section 1 or 737-300/400/500 MPD Volume 1 Section

4, Access Doors and Panels.

b. Set the STAB TRIM MAIN CUTOUT switch S272, on the control stand, to the CUTOUT

position.

c. Set the AUTOPILOT CRUISE TRIM CUTOUT switch S149, on the control stand, to the

CUTOUT position.

d. Open these circuit breakers shown below and attach the DO-NOT-CLOSE tags:

For Group 1 airplanes:

Location (Panel, Name Circuit Breaker Notes

Position)

FLIGHT CON- C00207

TROL STAB TRIM

CONT

P6-2, B13

FLIGHT CON- C00840

TROL STAB TRIM

ACTUATOR

P6-2, B11

STABILIZER TRIM C00849

SERVO

P18-0, A1

For Group 2 Configuration 1, and Group 3 airplanes:

Location (Panel, Name Circuit Breaker Notes

Position)

FLIGHT CON- C00207

TROL STAB TRIM

CONT

P6-2

FLIGHT CON- C00840

TROL STAB TRIM

ACTUATOR

P6-2

STABILIZER TRIM C00849

SERVO

P6-2

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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
e. Do a detailed inspection of the Horizontal Stabilizer Trim Actuator:

For Group 1 Configuration 1, Group 2 Configuration 1, and Group 3 Airplanes in accordance

with FIGURE 1.

For Group 1 Configuration 2 airplanes in accordance with FIGURE 2.

(1) Do a detailed inspection of all attachment points of the Lower and Upper Gimbal for cracks

and other damage. Inspect the areas around the holes and bushing. Make sure that the

Stabilizer Trim Actuator is correctly attached to the airplane structure. If any damage is

found, repair or replace the damaged parts. Refer to 737-100/200 AMM 27-41-81 or

737-300/400/500 AMM 27-41-81 and CMM 27-45-12 as an accepted procedure.

(2) Do a general visual inspection of the area under, on, and around the Stabilizer Trim

Actuator to see if grease is escaping from Ball Nut. Large amounts of grease present

around the Stabilizer Trim Actuator indicate that a faulty seal or lifted return tube may be

present on the Ball Nut.

If a large amount of grease is present due to a faulty seal or lifted/leaking return tube,

repair/replace the Stabilizer Trim Actuator in accordance with FIGURE 7 for Group 1

Configuration 1, Group 2 Configuration 1, and Group 3 Airplanes and in accordance with

FIGURE 8 for Group 1 Configuration 2 airplanes.

(3) Do a detailed inspection of the grease on and around the Ballscrew and Ball Nut for

existence of metallic particles, other solid particles, and corrosion products in the grease.

If metallic particles, or other solid particles, or corrosion products are found in the grease,

Repair/Replace the Stabilizer Trim Actuator:

For Group 1 Configuration 1, Group 2 Configuration 1, and Group 3 Airplanes in

accordance with FIGURE 7.

For Group 1 Configuration 2 Airplanes in accordance with FIGURE 8.

NOTE: If visible metallic particles are observed in the grease there may be some damage

in the Ballscrew/Ball Nut assembly. Normal wear of the Ballscrew actuator can

happen, but this will not release visible metallic particles in the grease.

(4) Check if any of the Ball Nut bearings are found in the vicinity of the Ball Nut, on the

Ballscrew, or directly below the Stabilizer Trim Actuator. If Ball Nut ball bearings are found

Repair/Replace the Horizontal Stabilizer Trim Actuator:

For Group 1 Configuration 1, Group 2 Configuration 1, and Group 3 airplanes in

accordance with FIGURE 7.

For Group 1 Configuration 2 airplanes in accordance with FIGURE 8.

NOTE: The Ball Nut ball bearings used inside the 737 Ball Nut are approximately 0.218

inch (5.6mm) in diameter.

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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
(5) Remove any old grease and dirt from the Ballscrew threads by wiping them with a clean,

dry, non-abrasive cloth.

(6) Do a detailed inspection of the Ball Nut Tube Retainers for deformation and corrosion or

lifted Return Tubes. If the Ball Nut Tube Retainers have deformation or corrosion or the

Return Tubes are lifted, Repair/Replace the stabilizer Trim Actuator:

For Group 1 Configuration 1, Group 2 Configuration 1, and Group 3 airplanes in

accordance with FIGURE 7.

For Group 1 Configuration 2 airplanes in accordance with FIGURE 8.

NOTE: Operators will find in the applicable Component Maintenance Manuals (CMM)

for Ballscrew Assembly the following terms: Ball Nut "Tube Retainers" (for

UMBRA CUSCINETTI, S.p.A. Ballscrew Assemblies), or BallNut "Return Tube

Covers" (LINEAR MOTION, LLC), or Ball Nut "Return Tube Clamps"

(SKYTRONICS, Inc.). The Term "Ball Nut Tube Retainers" will be used

throughout the Accomplishment Instructions.

(7) Do a detailed inspection of the Ballscrew for the following problems:

(a) Inspect the Ballscrew threads for cross-threading, distortion, or stripping. If you find

any of these conditions Repair/Replace the Stabilizer Trim Actuator in accordance

with:

For Group 1 Configuration 1, Group 2 Configuration 1, and Group 3 airplanes in

accordance with FIGURE 7.

For Group 1 Configuration 2 airplanes in accordance with FIGURE 8

(b) Check the Ballscrew for metallic particles, pitting, gouging, corrosion, spalling,

brinelling, cracks, and worn areas in the Ballscrew threads. If metallic particles, pitting,

gouging, corrosion, spalling, brinelling, cracks, or worn areas in the Ballscrew threads

is observed, repair/replace (as necessary) the Stabilizer Trim actuator:

For Group 1 Configuration 1, Group 2 Configuration 1, and Group 3 airplanes in

accordance with FIGURE 7

For Group 1 Configuration 2 airplanes in accordance with FIGURE 8

(c) Check for obvious differences in thread shape between thread grooves in the lower,

middle, and upper portions of the Ballscrew. If obvious differences in thread shape

between thread grooves in the lower, middle, and upper portions of the Ballscrew

are observed repair/replace (as necessary) the Stabilizer Trim Actuator:

For Group 1 Configuration 1, Group 2 Configuration 1, and Group 3 airplanes in

accordance with FIGURE 7.

For Group 1 Configuration 2 airplanes in accordance with FIGURE 8.

f. Remove the DO-NOT-CLOSE tags and close the circuit breakers shown below:

For Group 1 airplanes:

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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
Location (Panel, Name Circuit Breaker Notes

Position)

FLIGHT CON- C00207

TROL STAB TRIM

CONT

P6-2, B13

FLIGHT CON- C00840

TROL STAB TRIM

ACTUATOR

P6-2, B11

STABILIZER TRIM C00849

SERVO

P18-0, A1

For Group 2 Configuration 1, and Group 3 airplanes:

Location (Panel, Name Circuit Breaker Notes

Position)

FLIGHT CON- C00207

TROL STAB TRIM

CONT

P6-2

FLIGHT CON- C00840

TROL STAB TRIM

ACTUATOR

P6-2

STABILIZER TRIM C00849

SERVO

P6-2

g. Set the STAB TRIM MAIN CUTOUT switch, S272, on the control stand, to the NORMAL

position.

h. Push and hold the Stabilizer Trim Control switches on the Captain's Control Wheel (NOSE

UP or NOSE DOWN) to move the ballscrew to another location other than the current setting.

i. Make sure the operation is smooth and there is no unusual noise.

j. Set the STAB TRIM MAIN CUTOUT switch, S272 on the control stand, to the CUTOUT

position.

k. Make sure that the AUTOPILOT CRUISE TRIM CUTOUT switch S149, on the control stand,

is SET to the CUTOUT position.

l. Open this circuit breakers shown below and attach the DO-NOT-CLOSE tags:

For Group 1 airplanes:

Location (Panel, Name Circuit Breaker Notes

Position)

FLIGHT CON- C00207

TROL STAB TRIM

CONT

P6-2, B13

BOEING PROPRIETARY -

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Revision 1: January 07, 2010 737-27A1278

49 of 83

BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
Location (Panel, Name Circuit Breaker Notes

Position)

FLIGHT CON- C00840

TROL STAB TRIM

ACTUATOR

P6-2, B11

STABILIZER TRIM C00849

SERVO

P18-0, A1

For Group 2 Configuration 1, and Group 3 airplanes:

Location (Panel, Name Circuit Breaker Notes

Position)

FLIGHT CON- C00207

TROL STAB TRIM

CONT

P6-2

FLIGHT CON- C00840

TROL STAB TRIM

ACTUATOR

P6-2

STABILIZER TRIM C00849

SERVO

P6-2

m. Do a detailed inspection of the grease on the newly exposed area of the Ballscrew for metallic

particles, other solid particles, and corrosion products in the grease. If metallic particles, or

other solid particles, or corrosion products are found in the grease Repair/Replace the Stabilizer

Trim Actuator:

For Group 1 Configuration 1, Group 2 Configuration 1, and Group 3 airplanes in accordance

with FIGURE 7.

For Group 1 Configuration 2 airplanes in accordance with FIGURE 8.

NOTE: If visible metallic particles are observed in the grease there may be some damage

in the Ballscrew/Ball Nut assembly. Normal wear of the Ballscrew actuator can

happen, but this will not release visible metallic particles in the grease.

n. Remove any grease from the newly exposed portion of the Ballscrew threads by wiping them

with a clean, dry, non abrasive cloth.

o. Do a detailed inspection of the newly exposed Ballscrew for the following problems:

(1) Inspect the Ballscrew threads for cross-threading, distortion, or stripping. If you find any

of these conditions Repair/Replace the Stabilizer Trim actuator in accordance with:

For Group 1 Configuration 1, Group 2 Configuration 1, and Group 3 airplanes in

accordance with FIGURE 7.

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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
For Group 1 Configuration 2 airplanes in accordance with FIGURE 8.

(2) Check the Ballscrew for metallic particles, pitting, gouging, corrosion, spalling, brinelling,

cracks, and worn areas in the Ballscrew threads. If metallic particles, pitting, gouging,

corrosion, spalling, brinelling, cracks, or worn areas in the Ballscrew threads is observed,

repair/replace (as necessary) the Stabilizer Trim Actuator:

For Group 1 Configuration 1, Group 2 Configuration 1, and Group 3 in accordance with

FIGURE 7.

For Group 1 Configuration 2 airplane in accordance with FIGURE 8.

(3) Check for obvious differences in the thread shape between thread grooves in the lower,

middle, and upper portions of the Ballscrew. If obvious differences in thread shape between

thread grooves in the lower, middle, and upper portions of the Ballscrew are observed,

repair/replace (as necessary) the Stabilizer Trim Actuator:

For Group 1 Configuration 1, Group 2 Configuration 1, and Group 3 airplanes in

accordance with FIGURE 7.

For Group 1 Configuration 2 airplanes in accordance with FIGURE 8.

p. Apply grease (Lubricate) the Ballscrew and Ball Nut:

For Group 1 Configuration 1, Group 2 Configuration 1, and Group 3 airplanes in accordance

with FIGURE 4.

For Group 1 Configuration 2 airplanes in accordance with FIGURE 5.

Apply the grease slowly until clean, new, fresh grease exits through the grease vent. If clean,

new, fresh grease fails to exit the grease vent OR the upper seal, repair/replace the Stabilizer

Trim Actuator:

For Group 1 Configuration 1, Group 2 Configuration 1, and Group 3 airplanes in accordance

with FIGURE 7.

For Group 1 Configuration 2 airplanes in accordance with FIGURE 8.

(1) Inspect if grease exits the Ball Nut through Upper Seal, Lower Seal and around the Tube

Retainer areas:

(a) Clean, new fresh grease, that exits from the upper seal is also an acceptable indication

of proper lubrication of the Ball Nut.

(b) Small amounts of grease may exit the lower seal and is considered acceptable as

long as the general visual inspection of the under, on, and around the Stabilizer Trim

Actuator given in WORK PACKAGE 1 step 1.e.2 was found satisfactory.

(c) Small amount of grease may exit the ball nut through the Tube Retainer areas (from

the Return Tubes). If small amount of grease is observed around the Tube Retainer

do a detailed inspection of the Ball Nut Tube Retainers for deformation and corrosion

or lifted Return Tubes. If the Ball Nut Tube Retainers have deformation or corrosion

Repair/Replace (as necessary) the Stabilizer Trim Actuator:

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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
For Group 1 Configuration 1, Group 2 Configuration 1, and Group 3 airplanes in

accordance with FIGURE 7.

For Group 1 Configuration 2 airplanes in accordance with FIGURE 8.

If no damage of the Tube Retainers is found, the condition is acceptable.

If large amount of grease exits through the Tube Retainer areas, the Return Tubes

may be lifted and the Stabilizer Trim Actuator must be repaired or replaced:

For Group 1 Configuration 1, Group 2 Configuration 1, and Group 3 airplanes in

accordance with FIGURE 7.

For Group 1 Configuration 2 airplanes in accordance with FIGURE 8.

(2) Inspect the grease that exits the Ball Nut for indication of metallic particles, discolored

water, rust, or other solid particles. If any of these conditions exist Repair/Replace the

Stabilizer Trim Actuator:

For Group 1 Configuration 1, Group 2 Configuration 1, and Group 3 airplanes in

accordance with FIGURE 7.

For Group 1 Configuration 2 airplanes in accordance with FIGURE 8.

NOTE: If visible metallic particles are observed in the grease there may be some damage

in the Ballscrew/Ball Nut assembly. Normal wear of the Ballscrew Actuator can

happen but this will not release visible metallic particles in the grease.

2. Remove the DO-NOT-CLOSE tags and close the circuit breakers shown below:

For Group 1 airplanes:

Location (Panel, Name Circuit Breaker Notes

Position)

FLIGHT CON- C00207

TROL STAB TRIM

CONT

P6-2, B13

FLIGHT CON- C00840

TROL STAB TRIM

ACTUATOR

P6-2, B11

STABILIZER TRIM C00849

SERVO

P18-0, A1

For Group 2 Configuration 1, and Group 3 airplanes:

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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
Location (Panel, Name Circuit Breaker Notes

Position)

FLIGHT CON- C00207

TROL STAB TRIM

CONT

P6-2

FLIGHT CON- C00840

TROL STAB TRIM

ACTUATOR

P6-2

STABILIZER TRIM C00849

SERVO

P6-2

3. Close the service access door 3701. Refer to 737-200 MPD Volume 1 Section 1 or 737-300/400/500

MPD Volume 1 Section 4, Access Doors and Panels.

4. Put the airplane back to a serviceable condition.

NOTE: Make sure that you set the STAB TRIM MAIN CUTOUT to the serviceable position.

WORK PACKAGE 2 (GROUP 2 CONFIGURATION 2 Airplanes): Detailed Inspection and Lubrication

of the Horizontal Stabilizer Trim Actuator Ballscrew, Ball Nut, and attachment (Gimbal) fittings

1. Refer to Section 1.E., Compliance, Table 2, for the interval at which the Detailed Inspection and

Lubrication of Stabilizer Trim Actuator Ballscrew, Ball Nut, and attachment fittings (Gimbal Fittings)

need to be accomplished/repeated.

a. Get access to the Horizontal Stabilizer Trim Actuator assembly through service access door

3701. Refer to 737-200 MPD Volume 1 Section 1, Access Doors and Panels.

b. Set the STAB TRIM MAIN CUTOUT switch S272, on the control stand, to the CUTOUT

position.

c. Set the AUTOPILOT CRUISE TRIM CUTOUT switch S149, on the control stand, to the

CUTOUT position.

d. Open this circuit breakers shown below and attach the DO-NOT-CLOSE tags:

Location (Panel, Name Circuit Breaker Notes

Position)

FLIGHT CON- C00207

TROL STAB TRIM

CONT

P6-2

FLIGHT CON- C00840

TROL STAB TRIM

ACTUATOR

P6-2

STABILIZER TRIM C00849

SERVO

P6-2

BOEING PROPRIETARY -

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53 of 83

BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
e. Do a detailed inspection of the Horizontal Stabilizer Trim Actuator in accordance with FIGURE

3:

(1) Do a detailed inspection of all attachment points of the Lower and Upper Gimbal for cracks

and other damage. Inspect the area around the holes and bushing. Make sure that the

Stabilizer Trim Actuator is correctly attached to the airplane structure. If any damage is

found, repair or replace the damaged part. Refer to 737-100/200 AMM 27-41-81 and

CMM 27-45-12 as an accepted procedure .

(2) Do a detailed inspection of the oil on and around the Ballscrew and Ball Nut for existence

of metallic particles, other solid particles, and corrosion products in the oil. If metallic

particles, or other solid particles, or corrosion products are found in the oil, Repair/Replace

the Stabilizer Trim Actuator in accordance with FIGURE 9.

NOTE: If visible metallic particles are observed in the oil there may be some damage

in the Ballscrew/Ball Nut assembly. Normal wear of the Ballscrew actuator can

happen, but this will not release visible metallic particles in the oil.

(3) Check if any of the Ball Nut bearings are found in the vicinity of the Ball Nut, on the

Ballscrew, or directly below the Stabilizer Trim Actuator. If Ball Nut bearings are found

Repair/Replace the Horizontal Stabilizer Trim Actuator in accordance with FIGURE 9.

NOTE: The Ball Nut bearings used inside the 737 Ball Nut are approximately 0.218 inch

(5.6 mm) in diameter.

(4) Remove any old oil and dirt from the Ballscrew threads by wiping them with a clean, dry,

non-abrasive cloth.

(5) Do a detailed inspection of the Ball Nut Tube Retainers for deformation and corrosion or

lifted return tubes. If the Ball Nut Tube Retainers have deformation or corrosion or the

Return Tubes are lifted, Repair/Replace the Stabilizer Trim Actuator in accordance with

FIGURE 9.

(6) Do a detailed inspection of the Ballscrew for the following problems in accordance with

FIGURE 3.

(a) Inspect the Ballscrew threads for cross-threading, distortion, or stripping.

(b) Check the Ballscrew for metallic particles, pitting, gouging, corrosion, spalling,

brinelling, cracks and worn areas in the Ballscrew threads. If metallic particles, pitting,

gouging, corrosion, spalling, brinelling, cracks, or worn areas in the Ballscrew threads

is observed, repair/replace (as necessary) the Stabilizer Trim Actuator in accordance

with FIGURE 9.

(c) Check for obvious differences in thread shape between thread grooves in the lower,

middle, and upper portions of the Ballscrew. If obvious differences in thread shape

between thread grooves in the lower, middle, and upper portions of the Ballscrew is

observed, repair/replace (as necessary) the Stabilizer Trim Actuator in accordance

with FIGURE 9.

f. Remove the DO-NOT-CLOSE tags and close the circuit breakers shown below:

BOEING PROPRIETARY -

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Revision 1: January 07, 2010 737-27A1278

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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
Location (Panel, Name Circuit Breaker Notes

Position)

FLIGHT CON- C00207

TROL STAB TRIM

CONT

P6-2

FLIGHT CON- C00840

TROL STAB TRIM

ACTUATOR

P6-2

STABILIZER TRIM C00849

SERVO

P6-2

g. Set the STAB TRIM MAIN CUTOUT switch S272, on the control stand, to the NORMAL

position.

h. Push and hold the Stabilizer Trim Control switches on the Captain's Control Wheel (NOSE

UP or NOSE DOWN) to move the ballscrew to another location other than the current setting.

i. Make sure the operation is smooth and there is no unusual noise.

j. Set the STAB TRIM MAIN CUTOUT switch S272, on the control stand, to the CUTOUT

position.

k. Make sure that the AUTOPILOT CRUISE TRIM CUTOUT switch S149, on the control stand,

is SET to the CUTOUT position.

l. Open these circuit breakers shown below and attach the DO-NOT-CLOSE tags:

Location (Panel, Name Circuit Breaker Notes

Position)

FLIGHT CON- C00207

TROL STAB TRIM

CONT

P6-2

FLIGHT CON- C00840

TROL STAB TRIM

ACTUATOR

P6-2

STABILIZER TRIM C00849

SERVO

P6-2

m. Do a detailed inspection of the oil on the newly exposed area of the Ballscrew for metallic

particles, other solid particles, and corrosion products in the oil. If metallic particles, or other

solid particles, or corrosion products are found in the oil Repair/Replace the Stabilizer Trim

Actuator in accordance with FIGURE 9.

NOTE: If visible metallic particles are observed in the oil there may be some damage in the

Ballscrew/Ball Nut assembly. Normal wear of the Ballscrew actuator can happen,

but this will not release visible metallic particles in the oil.

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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
n. Remove any oil from the newly exposed portion of the Ballscrew threads by wiping them with

a clean, dry, non abrasive cloth.

o. Do a detailed inspection of the newly exposed area of the Ballscrew for the following problems

in accordance with FIGURE 3.

(1) Inspect the Ballscrew threads for cross-threading, distortion, or stripping.

(2) Check the Ballscrew for metallic particles, pitting, gouging, corrosion, spalling, brinelling,

cracks, and worn areas in the Ballscrew threads. If metallic particles, pitting, gouging,

corrosion, spalling, brinelling, cracks, or worn areas in the Ballscrew threads is observed,

remove, inspect, repair/replace (as necessary) the Stabilizer Trim Actuator in accordance

with FIGURE 9.

(3) Check for obvious differences in the thread shape between thread grooves in the lower

middle, and upper portions of the Ballscrew. If obvious differences in thread shape between

thread grooves in the lower, middle, and upper portion of the Ballscrew are observed,

remove, inspect, repair/replace (as necessary) the Stabilizer Trim Actuator in accordance

with FIGURE 9.

p. Apply grease (Lubricate) and fill oil reserver in accordance with FIGURE 6.

2. Remove the DO-NOT-CLOSE tags and close the circuit breakers shown below:

Location (Panel, Name Circuit Breaker Notes

Position)

FLIGHT CON- C00207

TROL STAB TRIM

CONT

P6-2

FLIGHT CON- C00840

TROL STAB TRIM

ACTUATOR

P6-2

STABILIZER TRIM C00849

SERVO

P6-2

3. Close the service access door 3701. Refer to 737-200 MPD Volume 1 Section 1, Access Doors

and Panels.

4. Put the airplane back to a serviceable condition.

NOTE: Make sure that you set the STAB TRIM MAIN CUTOUT to the serviceable position.

WORK PACKAGE 3 (GROUP 2, CONFIGURATION 2 AIRPLANES): Incorporate Boeing Service

Bulletin 737-27-1046, Revision 1, dated April 05, 1974 (If service bulletin is not already

incorporated)

1. For airplane with Horizontal Stabilizer Trim Actuator Ballscrew Assemblies with Oil Lubricators,

remove the existing Oil Lubricator Reservoirs and install a Grease Fitting in accordance with Boeing

Service Bulletin 737-27-1046 Revision 1, dated April 05, 1974.

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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
a. If you find the Stabilizer Ballscrew Assy 102J033-1 or 102J033-1 (OS) installed on the airplane,

remove and install Stabilizer Ballscrew Assy 102J033-3 or 102J033-502. If you install a

Stabilizer Ballscrew Assy 102J033-3 make sure that you incorporate Boeing Service Bulletin

737-27-1046 Revision 1, dated April 05, 1974 (if not already incorporated), before you install

this ballscrew assembly on the airplane.

NOTE: The Horizontal Stabilizer Trim Actuator Ballscrew Assembly 102J033-1 or 102J033-1

(OS) with Oil Lubricator can not be reworked to a Horizontal Stabilizer Trim Actuator

Ballscrew Assembly with grease lubrication fitting as given in Service Bulletin

737-27-1046.

NOTE: The Horizontal Stabilizer Trim Actuators with Oil Lubricators reworked to Horizontal

Stabilizer Trim Actuator with grease lubrication fittings in accordance with Service

Bulletin 737-27-1046 Revision 1, have to incorporate the SKYTRONICS, Inc. SB

93004 Service Bulletin, Dated September 01, 2005 in accordance with Work Package

4.

WORK PACKAGE 4 (ALL AIRPLANES): Rework the Stabilizer Trim Actuator Ballscrew assembly

1. For airplane with UMBRA CUSCINETTI Ballscrew Assemblies, install new Ball Nut Tube Retainers

in accordance with UMBRA CUSCINETTI, S.p.A. SB 07322-27-01 Service Bulletin, Rev 00, Dated

December 21, 2004.

a. After you incorporate UMBRA CUSCINETTI, S.p.A. SB 07322-27-01 Service Bulletin, hand

letter with a permanent ink or paste ink, in the area adjacent to the HSTA name plate (gear

box area) the following:

"UMBRA CUSCINETTI, S.p.A. SB 07322-27-01 IS INCORPORATED ON THIS HSTA IN

ACCORDANCE WITH SB 737-27A1278, WORK PACKAGE 4"

Apply BMS 10-60, Type 2, Clear, over the marking, to protect the marking from hydraulic fluid.

Refer to SOPM 20-50-10 as an accepted procedure for the marking process and marking

materials.

2. For airplane with LINEAR MOTION Ballscrew Assemblies, install new Ball Deflectors and Ball

Return Guide Clamps in accordance with LINEAR MOTION, LLC SB 7901708 Service Bulletin,

Dated July 26, 2005.

a. After you incorporate LINEAR MOTION, LLC SB 7901708 Service Bulletin, hand letter with

a permanent ink or paste ink, in the area adjacent to the HSTA name plate (gear box area)

the following:

"LINEAR MOTION, LLC SB 7901708 IS INCORPORATED ON THIS HSTA IN ACCORDANCE

WITH SB 737-27A1278, WORK PACKAGE 4"

Apply BMS 10-60, Type 2, Clear, over the marking, to protect the marking from hydraulic fluid.

Refer to SOPM 20-50-10 as an accepted procedure for the marking process and marking

materials.

3. For airplane with SKYTRONICS Ballscrew Assemblies, install the new Return Tube Clamps in

accordance with SKYTRONICS, Inc. SB 93004 Service Bulletin, Dated September 01, 2005.

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ALERT ALERT
a. If you find the Stabilizer Ballscrew Assy 102J033-1 or 102J033-1 (OS) installed on the airplane

remove and install Stabilizer Ballscrew Assy 102J033-502 or equivalent. If you install a

Stabilizer Ballscrew Assy 102J033-3 make sure to incorporate SB 737-27-1046 before you

install the Stabilizer Ballscrew Assy on the airplane.

b. After you incorporate SKYTRONICS, Inc. SB 93004 Service Bulletin, hand letter with a

permanent ink or paste ink, in the area adjacent to the HSTA name plate (gear box area) the

following:

"SKYTRONICS, Inc. SB 93004 IS INCORPORATED ON THIS HSTA IN ACCORDANCE

WITH SB 737-27A1278, WORK PACKAGE 4"

Apply BMS 10-60, Type 2, Clear, over the marking, to protect the marking from hydraulic fluid.

Refer to SOPM 20-50-10 as an accepted procedure for the marking process and marking

materials.

WORK PACKAGE 5 (ALL AIRPLANES): Remove the Stabilizer Trim Actuator for Repair/Overhaul

1. Remove and Repair/Overhaul the Horizontal Stabilizer Trim Actuator:

For Group 1 Configuration 1, Group 2 Configuration 1, and Group 3 airplane in accordance with

FIGURE 7.

For Group 1 Configuration 2 airplane in accordance with FIGURE 8.

For Group 2 Configuration 2 airplane in accordance with FIGURE 9.

Repeat the Overhaul as given in Paragraph 1.E., Compliance, Table 1 or Table 2, as applicable.

NOTE: Refer to 737-100/200 AMM 27-41-81 or 737-300/400/500 AMM 27-41-81 for instructions

to remove the Horizontal Stabilizer Trim Actuator. Refer to the applicable Component

Maintenance Manual: UMBRA CUSCINETTI, S.p.A. CMM 27-41-01, or LINEAR MOTION

LLC CMM 27-41-01, or SKYTRONICS Inc CMM 27-40-03 and CMM 27-45-11 for repairs

of the Horizontal Stabilizer Trim Actuator components.

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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
This Figure applies only to: Group 1-2, Configuration 1; Group 3.

FIGURE 1: HORIZONTAL STABILIZER TRIM ACTUATOR - DETAILED INSPECTION OF THE BALLSCREW,

BALL NUT, AND THE ATTACHMENT FITTINGS- (GROUP 1 CONFIGURATION 1, GROUP 2 CONFIGURATION

1, AND GROUP 3 AIRPLANES)

(SHEET 1 OF 4)

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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
FIGURE 1: HORIZONTAL STABILIZER TRIM ACTUATOR - DETAILED INSPECTION OF THE BALLSCREW,

BALL NUT, AND THE ATTACHMENT FITTINGS- (GROUP 1 CONFIGURATION 1, GROUP 2 CONFIGURATION

1, AND GROUP 3 AIRPLANES)

(SHEET 2 OF 4)

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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
FIGURE 1: HORIZONTAL STABILIZER TRIM ACTUATOR - DETAILED INSPECTION OF THE BALLSCREW,

BALL NUT, AND THE ATTACHMENT FITTINGS- (GROUP 1 CONFIGURATION 1, GROUP 2 CONFIGURATION

1, AND GROUP 3 AIRPLANES)

(SHEET 3 OF 4)

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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
STEP TASK NAME PART NUMBER QTY NOTES

Stabilizer Trim Actu- - (a)

ator attachment

points

1 Inspect

Do a general visual inspection to see if large

amount of grease exits the Ball Nut. (b)

Area Under, On, and -

Around Stabilizer

Trim Actuator

2 Inspect

3 Inspect Grease - (c) (d)

Ballscrew and Ball - for escaped Ball Nut ball bearings. (e)

Nut, Trim Actuator

Housing and area

below Stabilizer

Trim Actuator

4 Inspect

from Ballscrew threads by wiping with a clean,

dry, non-abrasive cloth.

5 Remove Grease -

Do a detailed inspection for deformation and

corrosion or lifted return tubes.

Ball Nut and Ball Nut

Tube Retainers

6 Inspect

7 Inspect Ballscrew - (f)

8 Move Ballscrew - to another location.

for existence of metal particles or other debris.

(b) (c)

Ballscrew and Ball -

Nut

9 Inspect

10 Inspect Ballscrew - (f)

(a) Do a detailed inspection of the lower and upper gimbal for cracks and other damage. Inspect the area

around the bushing. Make sure that the Stabilizer Trim Actuator is correctly attached to the airplane

structure.

(b) Large amount of grease present around the ball-screw indicate that a faulty seal or raised Ball Nut return

tubes may be present.

(c) Metallic particles in grease may be indication of degradation of the balls in the Ball Nut.

(d) Do a detail inspection on and around the Ballscrew and the Ball Nut for existence of metallic particles,

other solid particles, or corrosion products.

(e) The Ball Nut bearings are approximately 0.218 inch in diameter.

(f) Do a detailed inspection for cross-threading, distortion, stripping, metallic particles, pitting, gouging, corrosion, spalling, brinelling, cracks, worn areas and differenced in thread shape (between thread grooves in

the lower, middle, and upper portion of the Ballscrew). If any of the damage listed is observed, remove,

inspect, and repair/replace (as necessary) the Stabilizer Trim Actuator in accordance with 737 Umbra

Cuscinetti S.p.A. CMM 27-41-01, or Linear Motion LLC CMM 27-41-01, or Skytronics Inc CMM 27-40-03.

FIGURE 1: HORIZONTAL STABILIZER TRIM ACTUATOR - DETAILED INSPECTION OF THE BALLSCREW,

BALL NUT, AND THE ATTACHMENT FITTINGS- (GROUP 1 CONFIGURATION 1, GROUP 2 CONFIGURATION

1, AND GROUP 3 AIRPLANES)

(SHEET 4 OF 4)

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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
This Figure applies only to: Group 1, Configuration 2.

FIGURE 2: HORIZONTAL STABILIZER TRIM ACTUATOR - DETAILED INSPECTION OF THE BALLSCREW,

BALL NUT, AND THE ATTACHMENT FITTINGS - (GROUP 1, CONFIGURATION 2 AIRPLANES)

(SHEET 1 OF 4)

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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
FIGURE 2: HORIZONTAL STABILIZER TRIM ACTUATOR - DETAILED INSPECTION OF THE BALLSCREW,

BALL NUT, AND THE ATTACHMENT FITTINGS - (GROUP 1, CONFIGURATION 2 AIRPLANES)

(SHEET 2 OF 4)

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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
FIGURE 2: HORIZONTAL STABILIZER TRIM ACTUATOR - DETAILED INSPECTION OF THE BALLSCREW,

BALL NUT, AND THE ATTACHMENT FITTINGS - (GROUP 1, CONFIGURATION 2 AIRPLANES)

(SHEET 3 OF 4)

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65 of 83

BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
STEP TASK NAME PART NUMBER QTY NOTES

Stabilizer Trim Actu- - (a)

ator attachment

points

1 Inspect

Do a general visual inspection to see

if large amount of grease exits the

Ball Nut. (b)

Area Under, On, and -

Around Stabilizer

Trim Actuator

2 Inspect

3 Inspect Grease - (c) (d)

Ballscrew and Ball - for escaped Ball Nut bearings. (e)

Nut, Trim Actuator

Housing and area

below Stabilizer

Trim Actuator

4 Inspect

from Ballscrew threads by wiping with

a clean, dry, non-abrasive cloth.

5 Remove Grease -

Ball Nut and Ball Nut for corrosion or lifted return tubes.

Tube Retainers

6 Inspect

7 Inspect Ballscrew - (f)

8 Move Ballscrew - to another location.

for large amount of grease that exits

the Ball Nut and existence of metal

particles or other debris. (b) (c)

Ballscrew and Ball -

Nut

9 Inspect

10 Inspect Ballscrew - (f)

(a) Do a detailed inspection of the lower and upper gimbal for cracks and other damage. Inspect the

area around the bushings. Make sure that the Stabilizer Trim Actuator is correctly attached to the

airplane structure.

(b) Large amount of grease present around the ball-screw indicate that a faulty seal or raised Ball

Nut Return Tubes may be present.

(c) Metallic particles in grease may be indication of degradation of the balls in the Ball Nut.

(d) Do a detail inspection of the grease on and around the Ballscrew and the Ball Nut for existence

of metallic particles, other solid particles or corrosion products.

(e) The Ball Nut bearings are approximately 0.218 inch in diameter.

(f) Do a detailed inspection for cross-threading, distortion, stripping, metallic particles, pitting, gouging,

corrosion, spalling, brinelling, cracks, worn areas and differences in thread shape (between thread

grooves in the lower, middle, and upper portion of the Ballscrew). If any of the damage listed is

observed, remove, inspect, and repair/replace (as necessary) the Stabilizer Trim Actuator in accordance with 737 Umbra Cuscinetti S.p.A. CMM 27-41-01, or Linear Motion LLC CMM 27-41-

01, or Skytronics Inc CMM 27-40-03.

FIGURE 2: HORIZONTAL STABILIZER TRIM ACTUATOR - DETAILED INSPECTION OF THE BALLSCREW,

BALL NUT, AND THE ATTACHMENT FITTINGS - (GROUP 1, CONFIGURATION 2 AIRPLANES)

(SHEET 4 OF 4)

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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
This Figure applies only to: Group 2, Configuration 2.

FIGURE 3: HORIZONTAL STABILIZER TRIM ACTUATOR - DETAILED INSPECTION OF THE BALLSCREW,

BALL NUT, AND, AND THE ATTACHMENT FITTINGS - (GROUP 2, CONFIGURATION 2 AIRPLANES)

(SHEET 1 OF 4)

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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
FIGURE 3: HORIZONTAL STABILIZER TRIM ACTUATOR - DETAILED INSPECTION OF THE BALLSCREW,

BALL NUT, AND, AND THE ATTACHMENT FITTINGS - (GROUP 2, CONFIGURATION 2 AIRPLANES)

(SHEET 2 OF 4)

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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
FIGURE 3: HORIZONTAL STABILIZER TRIM ACTUATOR - DETAILED INSPECTION OF THE BALLSCREW,

BALL NUT, AND, AND THE ATTACHMENT FITTINGS - (GROUP 2, CONFIGURATION 2 AIRPLANES)

(SHEET 3 OF 4)

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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
STEP TASK NAME PART NUMBER QTY NOTES

Horizontal Stabilizer - (a)

Trim Actuator attachment points

1 Inspect

2 Inspect Grease - (b) (c)

Ballscrew and Ball - for escaped Ballnut bearings. (d)

Nut, Trim Actuator

Housing and area

below Horizontal

Stabilizer Trim Actuator

3 Inspect

from Ballscrew threads by wiping with

a clean, dry, non-abrasive cloth.

4 Remove Oil and Grease -

Do a detailed inspection for deformation and corrosion or lifted return

tubes.

Ball Nut and Ball Nut

Return Tubes

5 Inspect

6 Inspect Ballscrew - (e)

7 Move Ballscrew - to another location.

for existence of metal particles or

other debris. (b)

Ballscrew and Ball -

Nut

8 Inspect

Horizontal Stabilizer - (e)

Ballscrew

9 Inspect

(a) Do a detailed inspection of the lower and upper gimbal for cracks and other damage. Inspect the

area around the bushings. Make sure that the Stabilizer Trim Actuator is correctly attached to the

airplane structure.

(b) Metallic particles in grease may be indication of degradation of the balls in the Ball Nut.

(c) Do a detail inspection of the grease on and around the Ballscrew and the Ball Nut for existence

of metallic particles, other solid particles or corrosion products.

(d) The Ball Nut bearings are approximately 0.218 inch in diameter.

(e) Do a detailed inspection for cross-threading, distortion, stripping, metallic particles, pitting, gouging,

corrosion, spalling, brinelling, cracks, worn areas and differences in thread shape (between thread

grooves in the lower, middle, and upper portion of the Ballscrew). If any of the damage listed is

observed, remove, inspect, and repair/replace (as necessary) the Stabilizer Trim Actuator in accordance with 737 Skytronics Inc CMM 27-40-03.

FIGURE 3: HORIZONTAL STABILIZER TRIM ACTUATOR - DETAILED INSPECTION OF THE BALLSCREW,

BALL NUT, AND, AND THE ATTACHMENT FITTINGS - (GROUP 2, CONFIGURATION 2 AIRPLANES)

(SHEET 4 OF 4)

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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
This Figure applies only to: Group 1-2, Configuration 1; Group 3.

FIGURE 4: LUBRICATION OF THE HORIZONTAL STABILIZER TRIM ACTUATOR (GROUP 1

CONFIGURATION 1, GROUP 2 CONFIGURATION 1, AND GROUP 3 AIRPLANES)

(SHEET 1 OF 2)

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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
STEP TASK NAME PART NUMBER QTY NOTES

1 Apply Grease D00633 1 (a) (b)

if grease exits through the Upper

Seal, Lower Seal, and around the

Tube Retainer areas. (c) (d) (e)

Ballscrew and Ball - -

Nut

2 Inspect

that exits the Ball Nut for signs of

metallic particles, discolored water, rust, or other solid particles.

(f)

3 Inspect Grease - -

(a) in accordance with 737 Aircraft Maintenance Manual 737-100/200 AMM 12-22-41 or 737-300/400/500

AMM 12-22-41 untill clean, new, fresh grease exits through the grease vent.

(b) If clean, new, fresh grease fails to exit the grease vent OR the upper seal, repair/replace (as necessary)

the Stabilizer Trim Actuator in accordance with FIGURE 7 .

(c) Clean, new fresh grease, that exits from the upper seal is also an acceptable indication of proper lubrication of the Ball Nut.

(d) Small amounts of grease may exit the lower seal and is considered acceptable as long as the general

visual inspection of the area under, on, and around the stabilizer trim actuator in accordance with

Paragraph 3.B., Work Instructions - Work Package 1, Step 1.e.(2) was found satisfactory.

(e) Small amounts of grease may exit the ball nut through the Tube retainer areas (from the Return Tubes).

If small amount of grease is observed around the Tube Retainers do a detailed inspection of the Ball

Nut Tube Retainers for deformation and corrosion or lift Return Tubes. If the Ball Nut Tube Retainers

have deformation or corrosion Repair/Replace (as necessary) the Stabilizer Trim Actuator in accordance

with FIGURE 7. If no damage of the Tube Retainers is found the condition is acceptable. If large amount

of grease exits through the Tube Retainer areas, the Return Tubes may be lifted and the Stabilizer

Trim Actuator must be repaired or replaced (as necessary) in accordance with FIGURE 7.

(f) If visible metallic particles are observed in the grease there may be some damage in the Ballscrew/Ball

Nut assembly. Normal wear of the Ballscrew actuator can happen but this will not release visible

metallic particles in the grease.

FIGURE 4: LUBRICATION OF THE HORIZONTAL STABILIZER TRIM ACTUATOR (GROUP 1

CONFIGURATION 1, GROUP 2 CONFIGURATION 1, AND GROUP 3 AIRPLANES)

(SHEET 2 OF 2)

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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
This Figure applies only to: Group 1, Configuration 2.

FIGURE 5: LUBRICATION OF THE HORIZONTAL STABILIZER TRIM ACTUATOR (GROUP 1,

CONFIGURATION 2 AIRPLANES)

(SHEET 1 OF 2)

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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
STEP TASK NAME PART NUMBER QTY NOTES

1 Apply Grease D00633 1 (a) (b)

if grease exits through the Upper

Seal, Lower Seal and around the

Tube Retainer areas. (c) (d) (e)

Ballscrew and Ball - -

Nut

2 Inspect

that exits the Ball Nut for signs of

metallic particles, discolored water, rust, or other solid particles.

(f)

3 Inspect Grease - -

(a) in accordance with 737-300/400/500 AMM 12-22-41 untill clean, new, fresh grease exits through the

grease vent.

(b) If clean, new, fresh grease fails to exit the grease vent OR the upper seal, repair/replace (as necessary)

the Stabilizer Trim Actuator in accordance with FIGURE 8.

(c) Clean, new, fresh grease, that exits from the upper seal is also an acceptable indication of proper lubrication of the Ball Nut.

(d) Small amounts of grease may exit the lower seal and is considered acceptable as long as the general

visual inspection of the area under, on, and around the stabilizer trim actuator in accordance with

Paragraph 3.B., Work Instructions - Work Package 2, Step 1.e.(2) was found satisfactory.

(e) Small amounts of grease may exit the ball nut through the Tube retainer areas (from the Return Tubes).

If small amount of grease is observed around the Tube Retainers do a detailed inspection of the Ball

Nut Tube Retainers for deformation and corrosion or lift Return Tubes. If the Ball Nut Tube Retainers

have deformation or corrosion Repair/Replace (as necessary) the Stabilizer Trim Actuator in accordance

with FIGURE 8 . If no damage of the Tube Retainers is found the condition is acceptable. If large

amount of grease exits through the Tube Retainer areas, the Return Tubes may be lifted and the

Stabilizer Trim Actuator must be repaired or replaced (as necessary) in accordance with FIGURE 8 .

(f) If visible metallic particles are observed in the grease there may be some damage in the Ballscrew/Ball

Nut assembly. Normal wear of the Ballscrew actuator can happen but this will not release visible

metallic particles in the grease.

FIGURE 5: LUBRICATION OF THE HORIZONTAL STABILIZER TRIM ACTUATOR (GROUP 1,

CONFIGURATION 2 AIRPLANES)

(SHEET 2 OF 2)

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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
This Figure applies only to: Group 2, Configuration 2.

FIGURE 6: LUBRICATION OF THE HORIZONTAL STABILIZER TRIM ACTUATOR (GROUP 2,

CONFIGURATION 2 AIRPLANES)

(SHEET 1 OF 2)

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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
STEP TASK NAME PART NUMBER QTY NOTES

Refer to 737-100/200 AMM 12-

22-41.

1 Apply Grease D00633 -

in the lubricator reservoirs in accordance with 737-100/200 AMM

27-41-121.

2 Fill Oil MIL-L-7870 -

FIGURE 6: LUBRICATION OF THE HORIZONTAL STABILIZER TRIM ACTUATOR (GROUP 2,

CONFIGURATION 2 AIRPLANES)

(SHEET 2 OF 2)

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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
This Figure applies only to: Group 1-2, Configuration 1; Group 3.

FIGURE 7: HORIZONTAL STABILIZER TRIM ACTUATOR BALLSCREW AND BALL NUT - REPAIR/REPLACE

- (GROUP 1 CONFIGURATION 1, GROUP 2 CONFIGURATION 1, AND GROUP 3 AIRPLANES)

(SHEET 1 OF 2)

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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
STEP TASK NAME PART NUMBER QTY NOTES

Refer to 737-100/200 AMM 27-

41-81 or 737-300/400/500 AMM

27-41-81.

Horizontal Stabilizer - 1

Trim Actuator

1 Remove

Refer to Umbra Cuscinetti, S.p.A.

CMM 27-41-01, or Linear Motion,

LLC CMM 27-41-01, or Skytronics Inc CMM 27-40-03 and Boeing CMM 27-45-11.

Horizontal Stabilizer - 1

Trim Actuator

2 Repair/ Overhaul

Horizontal Stabilizer - 1 Refer to CMM 27-41-81. (b)

Trim Actuator

3 Install (a)

Horizontal Stabilizer - 1 (b)

Trim Actuator

4 Test

(a) Install a repaired or a new Horizontal Stabilizer Trim Actuator.

(b) If you replace a damaged Horizontal Stabilizer Trim Actuator with a serviceable Horizontal Stabilizer Trim

Actuator that is not new or not overhauled, then you must do the Detailed Inspection for the replacement

Horizontal Stabilizer Trim Actuator as given in this service bulletin, and the Horizontal Stabilizer Gearbox

End Play Test in accordance with OHM 27-45-11 .

FIGURE 7: HORIZONTAL STABILIZER TRIM ACTUATOR BALLSCREW AND BALL NUT - REPAIR/REPLACE

- (GROUP 1 CONFIGURATION 1, GROUP 2 CONFIGURATION 1, AND GROUP 3 AIRPLANES)

(SHEET 2 OF 2)

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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
This Figure applies only to: Group 1, Configuration 2.

FIGURE 8: HORIZONTAL STABILIZER TRIM ACTUATOR BALLSCREW AND BALL NUT - REPAIR/REPLACE

- (GROUP 1, CONFIGURATION 2 AIRPLANES)

(SHEET 1 OF 2)

BOEING PROPRIETARY -

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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
STEP TASK NAME PART NUMBER QTY NOTES

Refer to 737-300/400/500 AMM

27-41-81.

Horizontal Stabilizer - 1

Trim Actuator

1 Remove

Refer to Umbra Cuscinetti, S.p.A.

CMM 27-41-01, or Linear Motion,

LLC CMM 27-41-01, or Skytronics Inc CMM 27-40-03 and Boeing CMM 27-45-11.

Horizontal Stabilizer - 1

Trim Actuator

2 Repair/Overhaul

Refer to 737-300/400/500 AMM

27-41-81. (b)

Horizontal Stabilizer - 1

Trim Actuator

3 Install (a)

Horizontal Stabilizer - 1 (b)

Trim Actuator

4 Test

(a) Install a repaired or a new Horizontal Stabilizer Trim Actuator.

(b) If you replace a damaged Horizontal Stabilizer Trim Actuator with a serviceable Horizontal Stabilizer Trim

Actuator that is not new or not overhauled, then you must do the Detailed Inspection for the replacement

Horizontal Stabilizer Trim Actuator as given in this service bulletin, and the Horizontal Stabilizer Gearbox

End Play Test in accordance with OHM 27-45-11 .

FIGURE 8: HORIZONTAL STABILIZER TRIM ACTUATOR BALLSCREW AND BALL NUT - REPAIR/REPLACE

- (GROUP 1, CONFIGURATION 2 AIRPLANES)

(SHEET 2 OF 2)

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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
This Figure applies only to: Group 2, Configuration 2.

FIGURE 9: HORIZONTAL STABILIZER TRIM ACTUATOR BALLSCREW AND BALL NUT - REPAIR/REPLACE

- (GROUP 2, CONFIGURATION 2 AIRPLANES)

(SHEET 1 OF 2)

BOEING PROPRIETARY -

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BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
STEP TASK NAME PART NUMBER QTY NOTES

Refer to 737-100/200 AMM 27-

41-81.

Horizontal Stabilizer - 1

Trim Actuator

1 Remove

Refer to Skytronics Inc CMM 27-

40-03 and Boeing CMM 27-45-

11.

Horizontal Stabilizer - 1

Trim Actuator

2 Repair/Overhaul

Refer to 737-100/200 AMM 27-

41-81. (b)

Horizontal Stabilizer - 1

Trim Actuator

3 Install (a)

Horizontal Stabilizer - 1 (b)

Trim Actuator

4 Test

(a) Install a repaired or a new Horizontal Stabilizer Trim Actuator.

(b) If you replace a damaged Horizontal Stabilizer Trim Actuator with a serviceable Horizontal Stabilizer Trim

Actuator that is not new or not overhauled, then you must do the Detailed Inspection for the replacement

Horizontal Stabilizer Trim Actuator as given in this service bulletin, and the Horizontal Stabilizer Gearbox

End Play Test in accordance with OHM 27-45-11 .

FIGURE 9: HORIZONTAL STABILIZER TRIM ACTUATOR BALLSCREW AND BALL NUT - REPAIR/REPLACE

- (GROUP 2, CONFIGURATION 2 AIRPLANES)

(SHEET 2 OF 2)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: May 24, 2007

Revision 1 January 07, 2010 737-27A1278

82 of 83

BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT
Use this Inspection Report form to provide data to Boeing for the Horizontal Stabilizer Trim Actuator that is

inspected at specified intervals as given in this service bulletin:

Operator: _____________________________________ Today's Date: _________________________

Prepared by: ___________________________________ Title: _________________________________

Telephone Number: _____________________________ Base: _______________________________

Horizontal Stabilizer Trim Actuator part number and dash number: _______________________________

Stabilizer Trim Actuator Serial Number: ___________________________________

Date of inspection: ________________________

Airplane Variable Number/ Line Number: __________________________

Total number of Flight Cycles and Flight Hours on the airplane at the inspection date:

____________________ cycles ______________________hours

Metallic debris found in grease: YES ____ NO ____

Ball Nut bearings found in vicinity of the Ball Nut, Gear Box, or below the Horizontal Stabilizer Trim Actuator:

YES ____ NO ____

Ballscrew with threads damage: YES ____ NO ____

Horizontal Stabilizer Trim Actuator attachment points with cracks or other damage:

YES ____ NO ____

Upper and lower Gimbal with damage: YES ____ NO ____

Please provide a brief description of the damage, a sketch or a picture.

When a portion of the Detailed Inspection failed, give the completed inspection Report form and attachments,

sketches, or pictures to your Boeing Field Service Representative or send the Inspection Report directly to this

address:

Manager, Service Bulletin Engineering

Boeing Commercial Airplane Group

P.O. Box 3707, mail Code 2H-36

Seattle, WA 98124-2207

Appendix A: INSPECTION REPORT FORM FOR SB 737-27A1278

(SHEET 1 OF 1)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: May 24, 2007

Revision 1 January 07, 2010 737-27A1278

83 of 83

BOEING SERVICE BULLETIN 737-27A1278

ALERT ALERT